United States
Environmental Protection
Agency
Office of Air Quality
F'lanning and Standards
Research Triangle Park, NO
EPA 340/1 -90O26a
September 1990
Revised May 1 993
Stationary Source Compliajic.fi Training Series
JVEPA COURSE #380
INSPECTION TECHNIQUES
FOR FUGITIVE VOC
EMISSION SOURCES
Student Manual
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EPA 340/1-90-026a
Revised May 1993
Course Module #380
Inspection Techniques For
Fugitive VOC Emission Sources
Student Manual
Prepared by:
Pacific Environmental Services, Inc.
5001 South Miami Boulevard
PO Box 12077
Research Triangle Park, North Carolina 27709-2077
Contract No. 68-D2-0058
Work Assignment No. I-29
EPA Work Assignment Manager: Kirk Foster
EPA Project Officer: Aaron Martin
US. ENVIRONMENTAL PROTECTION AGENCY
Stationary Source Compliance Division
Office of Air Quality Planning and Standards
Washington, DC 20460
September 1990
Revised May 1993
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LECTURE 1
INTRODUCTION
Upon completion of this course, you will be able to conduct complete and effective Level 2
inspections of air pollution sources subject to fugitive VOC leak detection regulations. Such
inspections involve two separate but equally important activities: (1) evaluation of their data
acquisition techniques, and (2) evaluation of the leak detection program records and reports.
One of the goals of this course is to enable you, as a field inspector, to determine if plant
personnel are fully complying with the U.S. EPA Method 21 field monitoring techniques and if they
are adequately identify ing leaking equipment in VOC service. Inspectors must be thoroughly
familiar with VOC detector operating principles, calibration procedures, operating problems, and
leak screening techniques in order to confirm that the data acquisition portion of the leak detection
programs are in compliance.
Another goal of this course is to assist inspectors in evaluating the often complicated and
voluminous records which are an essential part of the leak detection programs. This is an especially
important portion of the course since most violations concern deficiencies in this area. It should
also be noted that fugitive VOC regulations are complicated and are not uniform from one category
to another. It is imperative that the inspector be thoroughly knowledgeable of the source specific
regulations before conducting an inspection.
After completing this course, you should be able to:
1. Determine which source categories are covered by Federal and State fugitive VOC
regulations.
2. Find the applicable Federal and State regulations.
3. Understand the overall approach of using both equipment standards and leak detection
and repair standards to achieve reductions in fugitive VOC emissions.
4. Determine if a source is complying with all the requirements of component
identification, component marking, equipment design, monitoring, repair,
recordkeeping, and reporting.
5. Understand the alternate standards.
6. List the VOC analyzer performance specifications required by U.S. EPA Method 21.
1-1
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7. Describe the basic operating principles of flame ionization analyzers, photoionization
analyzers, and catalytic combustion analyzers.
8. Select the proper VOC detector for a given VOC compound using published response
factor tables.
9. Describe why VOC analyzers used for leak detection do not provide a direct indication
of emission concentration and emission rate.
10. Evaluate source personnel's calibration procedures and records.
11. Evaluate field monitoring procedures used by source personnel to detect leaks from
pumps, valves, compressors, safety relief, values and other equipment in VOC service.
1-2
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LECTURE 2
INTRODUCTION TO FUGITIVE EMISSION Notes
REGULATIONS
The purpose of this lecture is to provide an overview of what the slide 2-1
equipment leak standards cover in terms of types of emissions, sources
regulated, and equipment regulated. After the completion of this lecture,
you should be able to identify and locate the Federal regulations for
equipment leaks in terms of the equipment and source categories covered;
to describe the various standards applicable to each type of equipment
covered; and to describe the differences between the standards.
OVERVIEW
Equipment leak standards are designed to reduce volatile organic Slide 2-2
compound (VOC) or volatile hazardous air pollutants (VHAP) emissions
that occur when certain process equipment leak. For example, pumps
have seals designed to keep the process fluid in the pump. These seals
may fail, thereby leaking to the environment the process fluid. These
standards are designed to reduce or eliminate emissions that occur as a
result of such leaks.
Equipment leak standards for VOC emissions are found in both Slide 2-3
Federal and State regulations. Equipment leak standards for VHAP
emissions are found in Federal regulations only.
Federal Regulations
The Federal regulations are either new source performance
standards (NSPSs) or national emission standards for hazardous air
pollutants (NESHAPs). NSPSs are implemented under Section 111 of the
Clean Air Act. They apply to newly constructed stationary sources.
Newly constructed sources are those that are constructed after the date an
NSPS is proposed in the Federal Register. In addition, existing stationary
sources (those that exist prior to the proposal date of an NSPS) can
become subject to an NSPS if they are modified or reconstructed after the
proposal date of the NSPS. NESHAPs are implemented under Section
112 of the Clean Air Act. They apply to both new and existing stationary
sources.
2-1
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Notes
An overriding purpose and long range goal of an NSPS is to
minimize emissions at all new and modified sources, wherever they are
located, in order to prevent new pollution problems from developing and
to enhance air quality as the Nation's industrial base is replaced. In
addition to achieving emissions reductions, standards of performance have
other benefits Standards of performance establish a degree of national
uniformity to air pollution standards, and, therefore, preclude situations in
which some States may attract new industries as a result of having relaxed
standards relative to other States. NESHAPs are developed to control
pollutants that are hazardous because they are carcinogens or cause other
serious diseases.
State Regulations
State regulation of equipment leaks for VOC emissions are
contained in State implementation plans (SIPs) and apply to existing
stationary sources. SIPs are plans that provide for the implementation,
maintenance, and enforcement of national primary and national secondary
ambient air quality standards. Promulgation of an NSPS requires States to
establish standards of performance for existing sources in the same
industry if the standard for new sources limits emissions of a designated
pollutant (i.e., a pollutant for which air quality criteria have not been
issued under Section 108 or which has not been listed as a hazardous
pollutant under Section 112).
WHY REGULATE VOCS AND VHAPS?
Volatile organic compounds, along with nitrogen oxides (NOX) and Slide 2-4
sunlight, contribute to produce ozone. Ozone is one of the criteria
pollutants for which national ambient air quality standards (NAAQS) exist
under Section 109 of the Clean Air Act. Nonattainment of the ozone
NAAQS is a serious problem in the United States. Reduction of ozone
formation can be accomplished by reducing emissions of VOC and NOX or
their exposure to sunlight. Controlling VOC is easier than NOX and, of
course, easier than controlling sunlight.
Note, however, that NSPSs are not directly designed to achieve the
ambient air quality goals. As noted earlier, an overriding purpose and
long range goal of an NSPS is to minimize emissions at all new and
modified sources, wherever they are located, in order to prevent new
pollution problems from developing and to enhance air quality as the
Nation's industrial base is replaced. Equipment leak standards will limit
2-2
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Notes
VOC emissions from all new, modified, or reconstructed process units and
will result in emission reductions well into the future. Even though these
reductions may not bear directly on attainment or nonattainment of
NAAQS for ozone, they will make room for future industrial growth
while preventing future air quality problems. The NSPS complements the
PSD (prevention of significant deterioration) and nonattainment rules as a
means of achieving and maintaining the NAAQS, while on a broader basis
they prevent new sources from making air pollution problems worse
regardless of the existing quality of ambient air.
Control of VHAP is implemented because such air pollutants are a
direct threat to human health. Benzene and vinyl chloride, the two
specific VHAP pollutants currently being regulated by equipment leak
standards, are both known human carcinogens.
In Slide 2-5, estimates of VOC emissions from selected source Slide 2-5
categories covered by these standards are presented. The emission
estimates shown for each of the source categories reflect estimates of
uncontrolled emissions from projected newly constructed, modified, and
reconstructed facilities over a five-year period (typically from 1980 to
1985). For example, EPA estimated that approximately 830 newly
constructed, modified, or reconstructed facilities would be affected by the
SOCMI equipment leak standards by 1985. If left uncontrolled, fugitive
VOC emissions from these 830 facilities would be approximately 91,500
tons per year. These numbers represent large quantities of organic
material being emitted into the atmosphere where ozone is formed.
Slide 2-6 shows the emission that would be emitted to the Slide 2-6
atmosphere after control. For example, the 830 SOCMI facilities would
emit approximately 41,000 tons of VOC from fugitive emission sources
after control. Thus, compliance with the equipment leak standards would
reduce fugitive emissions from these SOCMI sources by approximately 55
percent. For the other sources shown, the emission reduction percentages
are approximately 63 percent for petroleum refineries and 68 percent for
benzene sources.
REGULATED SOURCE CATEGORIES Slide 2-7
As of August 1, 1990, three source categories are regulated by
NSPSs for equipment leaks of VOC. These three source categories are:
1. The Synthetic Organic Chemical Manufacturing Industry
(SOCMI);
2-3
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Notes
2. Petroleum refineries; and
3. On-shore natural gas processing plants.
It is anticipated that equipment leak standards for VOC from
certain types of polymer manufacturing plants will have been promulgated
in October, 1990. Polymer manufacturing plants that would be affected
are those that produce polypropylene, polyethylene, polystyrene (crystal,
impact and expandable), and copolymers of these three major polymer
types.
Synthetic Organic Chemical Manufacturing Industry (SOCMD
The SOCMI is a broad source category, covering plants that
produce many types of organic chemicals. The EPA identified a list of
organic chemicals produced in a segment of this industry. The products
of this industry segment are derived from about ten basic petrochemical
feedstocks and are used as feedstocks in a number of synthetic products
industries. Organic chemicals produced in this segment of SOCMI include
acetone, methyl methacrylate, toluene, and glycine. The organic
chemicals in the segment of the SOCMI covered by equipment leak
standards are listed in §60.489 of the SOCMI equipment leak standard.
More formally, the SOCMI equipment leak standards apply to
affected facilities in the synthetic organic chemicals manufacturing
industry, which is defined as the industry that produces, as intermediates
or final products, one or more of the chemicals listed in §60.489.
Petroleum Refineries
Petroleum refineries are defined in the equipment leak standard
applicable to them as:
"... any facility engaged in producing gasoline, kerosene, distillate
fuel oils, residual oils, lubricants, or other products through the
distillation of petroleum, or through the redistillation, cracking, or
reforming of unfinished petroleum derivatives."
2-4
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Notes
On-Shore Natural Gas Processing Plants
Natural gas processing plants are defined as:
"... any processing site engaged in the extraction of natural gas
liquids from field gas, fractionation of mixed natural gas liquids to
natural gas products, or both."
"On-shore" means all facilities except those that are located in the
territorial seas or on the outer continental shelf.
Benzene
Unlike the NSPS VOC equipment leak standards that apply to
specifically defined source categories, the benzene equipment leak
standards apply to all sources except coke by-product plants. [Note: The
specific applicability of this standard and the others are discussed later in
the lecture.]
Vinyl Chloride
The vinyl chloride equipment leak standard identifies specific
sources subject to the standard. These sources are ethylene dichloride,
vinyl chloride, and poly vinyl chloride plants.
REGULATED EQUIPMENT Slide 2-8
j
There is a general set of equipment covered by all of the equipment
leak standards. These are listed in Slide 2-8. Product accumulator vessels
are only covered by the equipment leak standards for benzene. The vinyl
chloride fugitive emission standards also cover additional sources (loading
and unloading lines, agitators, slip gauges, opening of equipment, and in
process waste water). Except for agitators, the emissions from these
sources, however, are generally not considered "equipment leaks." The
equipment leak standards also identify requirements for closed vent
systems and control devices that may be used to comply with the
regulations. The following paragraphs describe the components covered
by the equipment leak standards.
Pumps
Pumps are used extensively in the SOCMI and petroleum refinery
industry, as well as in natural gas processing plants, for the movement of
organic fluids. The most widely used pump is the centrifugal pump.
2-5
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Notes
Other types of pumps may also be used, such as the positive-displacement,
reciprocating and.rotary action, and special canned and diaphragm pumps.
Chemicals transferred by pumps can leak at the point of contact
between the moving shaft and stationary casing. Consequently, all pumps
except the sealless type (canned-motor and diaphragm) require a seal at
the point where the shaft penetrates the housing in order to isolate the
pump's interior from the atmosphere. Packed and mechanical seals are
most commonly used.
Packed seals can be used on both reciprocating and rotary action
types of pumps. A packed seal consists of a cavity ("stuffing box") in the
pump casing filled with special packing material that is compressed with a
packing gland to form a seal around the shaft. A simple packed seal is
illustrated in Figure 2-1. To prevent buildup of frictional heat, lubrication
is required. A sufficient amount of either the liquid being pumped or
another liquid that is injected must be allowed to flow between the packing
and the shaft to provide the necessary lubrication. Degradation of this
packing and/or the shaft seal face after a period of usage can be expected
to eventually result in leakage of organic compounds to the atmosphere.
Mechanical seals are limited in application to pumps with rotating
shafts and can be further categorized as single and dual mechanical seals.
There are many variations to the basic design of mechanical seals, but all
have a lapped seal face between a stationary element and a rotating seal
sing. In a single mechanical seal application (see Figure 2-2 for an
illustration), the rotating-seal ring and stationary element faces are lapped
to a very high degree of flatness to maintain contact throughout their
entire mutual surface area. The faces are held together by a combination
of pressure supplied by a spring and the pump pressure transmitted,
through the liquid that is being pumped. An elastomer seals the rotating
face to the shaft. The stationary face is sealed,to the stuffing box with
another elastomer or gasket. As with packing, the faces must be
lubricated; however, because of the seal's construction, much less
lubrication is needed. There are many variations to the basic design, but
all have the lapped seal face between a stationary element and a rotating
seal ring. Again, if the seal becomes imperfect due to wear, the organic
compounds being pumped can leak between the seal faces and can be
emitted to the atmosphere.
2-6
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Pump stuffing box
Notes
\
\
\
\
^ \
SEES
X
y
r~
-
S
/
>
Fluid
end
Packing
^Packing gland
h-Seal face
Possible leak
area
Figure 2-1. Diagram of Simple Packed Seal
2-7
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Notes
Gland gasket
Pump stuffing box
Fluid
end
Rotating
seal ring
-Gland ring
.Insert packing
Stationary
element
-- Possible
leak
area
Figure 2-2. Diagram of Basic Single Mechanical Seal
2-8
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Notes
In a dual mechanical seal application (see Figure 2-3 for an
illustration), two seals can be arranged back-to-back or in tandem. In the
back-to-back arrangement, the two seals provide a closed cavity between
them. A barrier fluid, such as water or seal oil, is circulated through the
cavity. Because the barrier fluid surrounds the dual seal and lubricates
both sets of seal faces in this arrangement, the heat transfer and seal life
characteristics are much better than those of the single seal. In order for
the seal to function, the barrier fluid must be at a pressure greater than the
operating pressure of the stuffing box. As a result, some barrier fluid will
leak across the seal faces. Liquid leaking across the inboard face will
enter the stuffing box and mix with the process liquid. Barrier fluid going
across the outboard face will exit to the atmosphere. Therefore, the
barrier fluid must be compatible with the process liquid as well as with the
environment.
In a tandem dual mechanical seal arrangement, the seals face the
same direction. The secondary seal provides a backup for the primary
seal. A seal flush is used in the stuffing box to remove the heat generated
by friction. As with the back-to-back seal arrangement, the cavity
between the two tandem seals is filled with a barrier fluid. However, the
barrier fluid is at a pressure lower than that in the stuffing box.
Therefore, any leakage will be from the stuffing box into the seal cavity
containing the barrier fluid. Since this liquid is routed to a closed
reservoir, process liquid that has leaked into the seal cavity will also be
transferred to the reservoir. At the reservoir, the process liquid that has
leJced into the seal cavity will also be transferred to the reservoir. At the
reservoir, the process liquid could vaporize and be emitted to the
atmosphere. To ensure that VOCs or VHAPs do not leak from the
reservoir, the reservoir can be vented to a control device.
Another arrangement of dual seals which represents a relatively
new development, is the face-to-face arrangement. In this configuration
two rotating faces are mated with a common stationary. Barrier fluid may
be provided at higher or lower pressures than the stuffing box. As in the
tandem arrangement, if the barrier fluid is at a lower pressure than the
stuffing box, the barrier fluid reservoir would require venting to a control
device.
Another type of pump that has been used is the sealless pump,
which includes canned-motor and diaphragm pumps. In the canned-motor
pumps (see Figure 2-4), the cavity housing, the motor rotor, and the pump
casing are interconnected. As a result, the motor bearings run in the
process liquid and all shaft seals are eliminated. Because the process
liquid is the bearing-lubricant, abrasive solids cannot be tolerated.
Canned-motor pumps are being widely used for handling
2-9
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Notes
Possible leak into
sealing fluid
Seating-liquid
/ inlet
Seating-liquid
outlet
Fluid
end"
A
X !
ii
\ \i
\ J
\ I...
\ ->..
\ 1
\ 1
\ 1
Ll "\
\4> b
H^
x
— -Y
1
1
1
111
i;
j
i
t
j
|
fflff
•fooi
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a
sa
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IH
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^
"S
f
\
-1
1
SP;
il
r
J
^
fa
T?
u
)
pp.
1
-
\
Inner seat assembly
/ ocai IUOL* \
I \
NOuter seal assembly"
Figure 2-3. Diagram of Double Mechanical Seal
2-10
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DISCHARGE
N)
i
SUCTION
COOLANT CIRCULATING TUBE
STATOR LINER
L
IMPELLER
BEARINGS
I
CD
C/i
Figure 2-4. Diagram of Seal-less Canned Motor Pump
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Notes
organic solvents, organic heat transfer liquids, light oils, as well as many
toxic or hazardous liquids, or where leakage is an economic problem.
Diaphragm pumps (see Figure 2-5) perform similarly to piston and
plunger pumps. However, the driving member is a flexible diaphragm
fabricated of metal, rubber, or plastic. The primary advantage of this
arrangement is the elimination of all packing and shaft seals exposed to
the process liquid. This is an important asset when hazardous or toxic
liquids are handled.
Compressors
There are three basic types of compressors used in the industries
affected by these standards: centrifugal, reciprocating, and rotary. The
centrifugal compressor utilizes a rotating element or series of elements
containing curved blades to increase the pressure of a gas by centrifugal
force. Reciprocating and rotary compressors increase pressure by
confining the gas in a cavity and progressively decreasing the volume of
the cavity. Reciprocating compressors usually employ a piston and
cylinder arrangement, while rotary compressors utilize rotating elements
such as lobed impellers or sliding vanes.
As with pumps, sealing devices are required to prevent leakage
from compressors. Rotary shaft seals for compressors may be chosen
from several different types: labyrinth, restrictive carbon rings,
mechanical contact, and liquid film. Figure 2-6 is an illustration of a
liquid-film compressor shaft seal. All of these seal types are leak
restriction devices; none of them completely eliminate leakage. Many
compressors may be equipped with ports in the seal area to evacuate
collected gases.
The labyrinth type of compressor seal is composed of a series of
close tolerance, interlocking "teeth" which restrict the flow of gas along
the shaft. Many variations in "tooth" design and materials of construction
are available. Although labyrinth type seals have the largest leak potential
of the different types, properly applied variations in "tooth" configuration
and shape can reduce leakage by up to 40 percent over a straight pass type
labyrinth.
Restrictive carbon ring seals consist of multiple stationary carbon
rings with close shaft clearances. This type of seal may be operated dry
with a sealing fluid or with a buffer gas. Restrictive ring seals can
achieve lower leak rates than the labyrinth type.
2-12
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Notes
Diaphragm
Piston
Figure 2-5. Diagram of Diaphragm Pump
2-13
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Notes
INNER
BUSHING
INTERNAL
GAS
PRESSURE
OIL IN FROM RESERVOIR
OUTER
BUSHING
CONTAMINATED
OIL OUT
TO RESERVOIR
OIL OUT
ATMOSPHERE
Figure 2-6. Diagram of Liquid-Film Compressor Shaft Seal
2-14
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Notes
Mechanical contact seals are a common type of seal for rotary
compressor shafts, and are similar to the mechanical seals described for
pumps. In this type of seal, the clearance between the rotating and
stationary elements is reduced to zero. Oil or another suitable lubricant is
supplied to the seal faces. Mechanical seals can achieve the lowest leak
rates of the types identified above, but they are not suitable for all
processing
Packed seals are used for reciprocating compressor shafts. As with
pumps, the packing in the stuffing box is compressed with a gland to form
a seal. Packing used on reciprocating compressor shafts is often of the
"chevron" or netted V type. Because of safety considerations, the area
between the compressor seals and the compressor motor (distance piece) is
normally enclosed and vented outside of the compressor building. If
hydrogen sulfide is present in the gas, then the vented vapors are normally
flared.
Reciprocating compressors may employ a metallic packing plate
and nonmetallic partially compressible (i.e., Graffoil,®, Teflon®) material
or oil wiper rings to seal shaft leakage to the distance piece.
Nevertheless, some leakage into the distance piece may occur.
In addition to having seal types like those used for pumps,
centrifugal compressors can be equipped with a liquid-film seal. The seal
is a film oil that flows between the rotating shaft and the stationary gland.
The oil that leaves the compressor from the pressurized system side is
under the system internal gas pressure and is contaminated with the gas.
When this contaminated oil is returned to the open oil reservoir, process
gas and entrained VOC and VHAP can be released to atmosphere.
Pressure Relief Devices
Engineering codes require that pressure-relieving devices or
systems be used in applications where the process pressure may exceed the
maximum allowable working pressure of the vessel. The most common
type of pressure-relieving device used is the pressure relief valve.
Typically, relief valves are spring-loaded (see Figure 2-7) and designed to
open when the process pressure exceeds a set pressure, allowing the
release of vapors or liquids until the system pressure is reduced to its
normal operating level. When the normal pressure is re-attained, the
valve reseats, and a seal is again formed. The seal is a disk on a seat,
and the possibility of a leak through this seal makes the pressure relief
valve a potential source of VOC and VHAP fugitive emissions. The
potential causes of leakage from relief valves are:
2-15
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Notes
Spring
Possible
Leak Area
Nozzle
Process Side
Figure 2-7. Diagram of a Spring-Loaded Relief Valve
2-16
-------
Notes
"simmering or popping", a condition due to the system pressure being
close to the set pressure of the valve, improper reseating of the valve after
a relieving operation, and corrosion or degradation of the valve seat.
Rupture disks may also be used in process units (see Figure 2-8).
These disks are made of a material that ruptures when a set pressure is
exceeded, thus allowing the system to depressurize. The advantage of a
rupture disk is that the disk seals tightly ad does not allow any VOC or
VHAP to escape from the system under normal operation. However,
when the disk does rupture, the system depressurizes until atmospheric
conditions are obtained, unless the disk is used in series with a pressure
relief valve.
Sampling Connections
The operation of process units is checked periodically by routine
analysis of feedstocks and products. To obtain representative samples for
these analyses, sampling lines must first be purged. If this flushing liquid
is not returned to the process, it could be drained onto the ground or into
a process drain, where it would evaporate and release VOC or VHAP to
the atmosphere. Two closed-loop sampling systems are illustrated in
Figure 2-9.
Open-Ended Valves or Lines
Some valves are installed in a system so that they function with the
downstream line open to the atmosphere. Open-ended lines are used
mainly in intermittent service for sampling and venting. Examples are
purge, drain, and sampling lines. Some open-ended lines are needed to
preserve product purity. These are normally installed between multi-use
product lines to prevent products from collecting in cross-tie lines due to
valve seat leakage. A faulty valve seat or incompletely closed valve
would result in leakage through the valve and fugitive VOC or VHAP
emissions to the atmosphere.
Process Valves
One of the most common pieces of equipment in plants affected by
these standards is the valve. The types of valves commonly used are
control, globe, gate, plug, ball, relief, and check valves (see Figures 2-10
and 2-11). All except the relief valve (which is discussed above) and
check valve are activated through a valve stern, which may have either a
rotational or linear motion, depending on the specific design. This stem
requires a seal to isolate the process fluid inside the valve from
2-17
-------
Notes
Tension-adjustment
thimble
CONNECTION FOR
PRESSURE GAUGE
& BLEED VALVE
FROM SYSTEM
Figure 2-8. Diagram of Rupture Disk Installation
Upstream of a Relief Valve
2-18
-------
SAMPLE
CONTAINER
Notes
PROCESS LINE
PROCESS LINE
SAMPLE
CONTAINER
Figure 2-9. Diagram of Two Closed-Looped Sampling Systems
2-19
-------
Notes
HANDWHEEL
STEM
PACKING NUT
DISK
BODY
PACKING
BONNET
SEAT
Figure 2-10. Diagram of a Globe Valve with a Packed Seal
2-20
-------
Notes
Ball
Potential
Leak Areas
Figure 2-11. Diagram of a Ball Valve
2-21
-------
Notes
the atmosphere. The possibility of a leak through this seal makes it a
potential source of fugitive emissions. Since a check valve has no stem or
subsequent packing gland, it is not considered to be a potential source of
fugitive emissions.
Sealing of the stem to prevent leakage can be achieved by packing
inside a packing gland or O-ring seals. Valves that require the stem to
move in and out with or without rotation must utilize a packing gland.
Conventional packing glands are suited for a wide variety of packing
material. The most common are various types of braided asbestos that
contain lubricants. Other packing materials include graphite, graphite-
impregnated fibers, and tetrafluorethylene polymer. The packing material
used depends on the valve application and configuration. These
conventional packing glands can be used over a wide range of operating
temperatures. At high pressures, these glands must be quite tight to attain
a good seal.
Elastomeric O-rings are also used for sealing process valves.
These O-rings provide good sealing, but are not suitable where there is
sliding motion through the packing gland. Those seals are rarely used in
high pressure service and operating temperatures are limited by the seal
material.
Bellows seals are more effective for prevention process fluid leaks
than the conventional packing gland or any other gland-seal arrangement.
This type of seal incorporates a formed metal bellows that makes a barrier
between the disc and body, bonnet joint (see Figure 2-12). The bellows is
the weak point of type system and service life can be quite variable.
Consequently, this type of seal is normally backed up with a conventional
packing gland and is often-fitted with a leak detector in case of failure.
A diaphragm may be used to isolate the .working parts of the valve
and the environment from the process liquid. Figures 2-13 and 2-14
illustrate two types of diaphragm seals. The diaphragm may also be used
to control the flow of the process fluid. In this design, a compressor
component pushes the diaphragm toward the valve bottom, throttling the
flow. The diaphragm and compressor are connected in a manner so that it
is impossible for them to be separated under normal working conditions.
When the diaphragm reaches the valve bottom, it seats firmly against the
bottom, forming a leak-proof seal. This configuration is recommended for
fluids containing solid particles and for medium-pressure service.
Depending on the diaphragm material, this type of valve can be used at
temperatures up to 205 °C and in
2-22
-------
Notes
STEM
YOKE
BELLOWS
Figure 2-12. Diagram of a Sealed Bellows Valve
2-23
-------
Notes
Weir
Diaphragm
Figure 2-13. Diagram of a Weir Diaphragm Seal
Diaphragm
Figure 2-14. Diagram of a Bonnet Diaphragm Seal
2-24
-------
Notes
severe acid solutions. If failure of the seal occurs, a valve employing a
diaphragm seal can become a source of fugitive emissions.
Flanges and Other Connectors
Flanges are bolted, gasket-sealed junctions used wherever pipe or
other equipment such as vessels, pumps, valves, and heat exchangers may
require isolation or removal. Connectors are all other nonwelded fittings
that serve a similar purpose to flanges, that also allow bends in pipes
(ells), joining two pipes (couplings), or joining three or four pipes (tees or
crosses). The connectors are typically threaded.
Flanges may become fugitive emission sources when leakage
occurs due to improperly chosen gaskets or poorly assembled flanges.
The primary cause of flange leakage is due to thermal stress that piping or
flanges in some services undergo; this results in the deformation of the
seal between the flange faces. Threaded connectors may leak if the
threads become damaged or corroded, or if tightened without sufficient
lubrication or torque.
Product Accumulator Vessels
Product accumulator vessels include overhead and bottoms receiver
vessels utilized with fractionation columns, and product separator vessels
utilized in series with reactor vessels to separate reaction products.
Accumulator vessels can be vented directly to atmosphere or indirectly to
atmosphere through a blowdown drum or vacuum system. When an
accumulator vessel contains -benzene and vents to atmosphere, benzene
emissions can occur. This equipment is covered only by the benzene
equipment leak standard.
Agitators
Agitators are used to stir or blend chemicals. Like pumps and
compressors, agitators may leak organic chemicals at the point where the
shaft penetrates the casing. Consequently, seals are required to minimize
fugitive emissions from agitators. Four seal arrangements are commonly
used with agitators; they include: compression packing (packed seal),
mechanical seals, hydraulic seals, and lip seals. Packed seals for agitators
are very similar in design and application to the packed seals for pumps.
Although mechanical seals are more costly than the other three seal
arrangements, they offer a greatly reduced leakage rate to offset their
higher cost. The maintenance frequency of mechanical seals is, also, one-
half to one-fourth that of packed seals. In fact, at pressures greater than
2-25
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Notes
1140 kPa (150 psig), the leakage rate and maintenance frequency are so
superior that the use of packed seals on agitators is rare. As with packed
seals, the mechanical seals for agitators are similar to the design and
application of mechanical seals for pumps.
The hydraulic seal is the simplest and least used agitator shaft-seal.
In this type of seal, an annular cup attached to the process vessel contains
a liquid that is in contact with an inverted cup attached to the rotating
agitator shaft. The primary advantage of this seal is that it is non-contact
seal. However, this seal is limited to low temperatures and pressures and
can only handle very small pressure fluctuations. Organic chemicals may
contaminate the seal liquid and then be released into the atmosphere as
fugitive emissions.
A lip seal can be used on a top-entering agitator as a dust or vapor
seal. The sealing element is a spring-loaded elastomer. Lip seals are
relatively inexpensive and easy to install. Once the seal has been installed
the agitator shaft rotates in continuous contact with the lip seal. Pressure
limits of the seal are 2 to 3 psi because it operates without lubrication.
Operating temperatures are limited by the characteristics of the elastomer.
Fugitive emissions can be released through this seal when this seal wears
excessively or the operating pressure surpasses the pressure limits of the
seal.
Closed Vent Systems and Control Devices
A closed-vent system can be used to collect and dispose of gaseous
,VPC emissions resulting from seal oil degassing vents, pump and
compressor seal leakage, relief valve leakage, and relief valve discharges
due to overpressure operation., A closed vent system consists of piping
connectors, flame arresters, and where needed, flow inducing devices.
Closed vent systems are designed and operated such that all VOC
emissions are transported to a control device without leakage to the
atmosphere.
Several types of control devices could be used to dispose of VOC
and VHAP emissions captured in the closed-vent system. Incineration,
carbon adsorption, and condensation are three control methods that are
typically applied. Control efficiencies of the three methods are dependent
on specific operating characteristics of types of emissions. Typically,
enclosed combustion devices (boilers, process heaters, thermal arid
catalytic incinerators) can achieve better than 95 percent destruction
efficiencies. The key parameters affecting destruction efficiency are
residence time and temperature. Carbon adsorption systems can achieve
95 to 99 percent control efficiency through proper design and operation,
2-26
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Notes
while condensation systems can achieve capture efficiencies of 90 percent
or more.
Flares are commonly found at plants subject to these standards.
Several types of flares may be found: steam-assisted, air-assisted,
nonassisted, ground, dual-flare systems. Certain flares have been
demonstrated to achieve destruction efficiencies equal to those of enclosed
combustion devices provide certain design specifications are met (heat
content and exit velocity).
TYPES OF STANDARDS Slide 2-9
The regulations for equipment leaks incorporate three different
types of standards. These are: (1) performance standards; (2) equipment
standards: and (3) work practice standards. For most equipment, more
than one of these types of standards are applicable.
Performance Standards
As defined in the Clean Air Act, a "standard of performance"
refers to an allowable emission limit (e.g., a limit on the quantity of a
pollutant emitted over a specified time period or a percent reduction). For
most sources of equipment leaks, EPA determined that it is not feasible to
prescribe performance standards, because except in those cases in which
the performance standard can be set at "no detectable emissions" the only
way to measure emissions from equipment leak sources such as pumps,
pipeline valves, and compressors would be to use a bagging technique for
each component in a process unit. The EPA determined that the large
number of components and their dispersion over large areas would make
such a requirement economically impracticable.
The standard of performance included in these standards is "no
detectable emissions." A source is demonstrated to be operating with "no
detectable emissions" as indicated by an instrument reading of less than
500 ppm above background. The "no detectable emissions" standard is, in
general, applicable to pumps, compressors, pressure relief devices in
gas/vapor service, and valves.
The equipment leak standards also contain standards of
performance for closed vent systems and several types of control devices.
Closed vent system are to meet the "no detectable emissions" standard of
performance. Vapor recovery systems (e.g., carbon adsorbers,
condensers, absorbers) are to have control efficiencies of at least 95
2-27
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Notes
percent. This standard of performance (95 percent reduction) is also
applicable to enclosed combustion devices.
When it is not possible to specify a standard of performance,
equipment, design, work practice, or operational standards, or combustion
thereof can be promulgated. The equipment leak standards contain all of
these alternatives.
Equipment. Design, and Operational Standards
As noted above, the equipment leak standards contain each of these
three types of standards.
Equipment Standards
Equipment standards refer to those instances where the regulation
specifies the use of a particular piece of equipment. If that piece of
equipment is used, then the component is in compliance. For example,
open-ended valves or lines are to be equipped with a cap, blind flange,
plug, or a second valve. An open-ended lines that is capped, for example,
is in compliance with the regulation. Other fugitive emission sources for
which equipment specifications exist are pumps, compressors, sampling
connections, and product accumulator vessels.
Design Standards
Design standards refer to those instances where the regulations
specify how the equipment is to be designed. For example, enclosed
combustion devices that meet design specifications related to minimum
residence times and temperatures can be used to comply with these
standards. Flares also can be used provided they meet certain design
specifications.
Operational Standards
Operational standards refer to those instances where the regulations
specify how a piece of equipment is to be operated. If the equipment is
operated in the specified manner, then it is in compliance with the
regulations. For example, each open-ended valve or line that is equipped
with a second valve is to be operated in a manner such that the valve on
the process fluid end is closed before the second valve is closed.
Work Practice Standards
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Notes
Work practice standards refer primarily to the leak detection and
repair (LDAR) programs implemented by these regulations. These LDAR
programs rely on the monitoring of various components at regular
intervals in order to determine whether or not they are leaking. If they
are leaking, then the repair part of LDAR program is instituted.
Components covered by LDAR programs are pumps and valves.
The regulations also require certain components to be monitored to
determine if there is "evidence of a leak." Components covered by this
requirement are pumps and valves in heavy liquid service, pressure relief
devices in liquid service, and flanges and other connectors.
COMPARISON OF REGULATIONS
The various equipment leak standards contain many similarities. Slide 2-10 and
This is due primarily to the fact that the best control technology applicable Slide 2-11
to a specific component type is the same regardless of whether it is in a
SOCMI plant, a petroleum refinery, an on-shore natural gas processing
plant, or a vinyl chloride plant. Thus, there is little need to enact
different equipment leak standards across different source categories.
Nevertheless, there are differences between source categories that affect
the selection of components to be covered, the applicability of the
standards to certain plants, etc. Similarities are reviewed first and then
differences. Neither discussion is intended to be comprehensive, and
additional examples of differences are identified throughout the lecture.
Covered Equipment
For the most part, the standards cover the same equipment:
pumps, compressors, valves, open-ended valves and lines, pressure relief
devices, sampling connections and flanges and other connectors. In
addition to these components, the benzene equipment leak standard covers
product accumulator vessels and the vinyl chloride equipment leak
standards covers a number of additional components such as agitators and
in process waste water. Some of the standards exempt certain equipment
based on a number of factors such as type (e.g., reciprocating
compressor), location, and plant size. The petroleum refinery and on-
shore natural gas processing plant standards, for example, exempt from
the standards certain equipment located in the Alaskan North Slope.
Leak Definitions
The standards contain the same leak definitions. For pumps, a leak
is detected if:
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Notes
1. An instrument reading of 10.000 ppm or greater is measured,
or
2. There are indications of liquids dripping from the pump seal.
For compressors, a leak is detected if the sensor indicates failure of
the seal system, the barrier system, or both. [The standards require each
barrier fluid system to be equipped with a sensor that will detect failure of
the seal system, barrier fluid system, or both.]
For valves in gas/vapor service or light liquid service or in VHAP
service, a leak is detected if an instrument reading of 10,000 ppm or
greater is measured.
For pumps and valves in heavy liquid service, pressure relief
devices in liquid service, and flanges and other connectors, a leak is
detected if an instrument reading of 10,000 ppm or greater is measured.
Definitions of "In Light Liquid Service" and "In Heavy Liquid
Service"
While all of the NSPS use the same definition for "in light liquid
service" and "in heavy liquid service," the on-shore natural gas processing
plant standards provide alternative definitions to those found in the
SOCMI standards. The petroleum refinery standard also provides an
alternative definitive for "in light liquid service."
Sampling Method
All of the standards require the use of the same sampling method
for detecting a leak. This sampling method is contained in Method 21.
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Notes
Monitoring Frequency
Although fairly consistent among the Federal regulations, State
regulations frequently cite different monitoring intervals than the Federal
regulations for the same component.
Component Labeling
All components subject to Subpart V (Part 61) are required to be
marked in such a manner that they can be distinguished readily from other
pieces of equipment. Components subject to one of the NSPS equipment
leak standards need only to be so marked when a leak is detected.
Repair/Retest Procedures
Once a leak is detected, it is to be repaired to eliminate the leak.
"Repaired" means that equipment is adjusted, or otherwise altered, in
order to eliminate a leak as indicated by one of the following: an
instrument reading of 10,000 ppm or greater, indication of liquids
dripping, or indication by a sensor that a seal or barrier fluid system has
failed. Repairing a leak, therefore, means that the piece of equipment is
retested to determine whether a leak is detected. If no leak is detected,
then it is repaired. If a leak is detected, then it is not repaired.
The procedures for repairing and retesting detected leaks are the
same in each standard. Covered are when first attempts at repair are
required, when leaks are to be repaired, and conditions under which repair
can be delayed.
Recordkeeping and Reporting
In general, the reporting and recordkeeping requirements are the
same between the standards.
At this point in the lecture, major areas in the standards will be Slide 2-12
covered. These areas are shown in Slide 2-12.
DEFINITIONS Slide 2-13
The first major area deals with defining various terms used in the
standards. Most of these terms are defined in §60.481 and §61.241, and Slide 2-14
are the same between these sections. The other standards may have
different definitions or supplement the ones in these two sections. The
definitions reviewed here are selected ones; others are contained in the
2-31
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Notes
standards. These were selected to assist in understanding how the
standards are applied.
Affected Facility
An affected facility is an emission source or group of emission
sources to which a standard applies.
The various definitions of affected facility for the three NSPS
equipment leak standards are shown below:
Standard
Affected Facility
SOCMI
the group of all equipment within a
process unit
Petroleum refinery
each compressor
the group of all equipment within
process unit
On-shore natural gas
processing plants
a compressor in VOC service or in
wet gas service
the group of all equipment except
compressors within a process unit
For the NESHAP equipment leak standards, each individual piece
of equipment (e.g., each pump, each compressor) is the affected facility.
Process Unit
Each standard defines process unit in two parts. The first part
makes the definition specific to the subpart. The second part defines the
characteristic of a process unit, and is the same for each standard. The
equipment leak standards for benzene and vinyl chloride incorporate the
definition found hi the VHAP standard.
2-32
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Notes
Standard
Process Unit Definition
SOCMI
Components assembled to produce; as inter-
mediate or final products, one or more of the
chemicals listed in §60.489 of this part.
A process unit can operate independently if
supplied with sufficient feed or raw materials
and sufficient storage facilities for the product.
Petroleum refinery
Components assembled to produce intermediate
or final products from petroleum, unfinished
petroleum derivatives, or other intermediates.
A process unit can operate independently if
supplied with sufficient feed or raw materials
and sufficient storage facilities for the product.
On-shore natural gas
processing plants
Equipment assembled for the extraction of
natural gas liquids from field gas, the
fractionation of liquids into natural gas
products, or other operations associated with the
processing of natural gas products.
A process unit can operate independently if
supplied with sufficient feed or raw materials
and sufficient storage facilities for the product.
VHAP
Equipment assembled to produce VHAP or its
derivatives as intermediates or final products, or
equipment assembled to use a VHAP in the
production of a product.
A process unit can operate independently if
supplied with sufficient feed or raw materials
and sufficient storage facilities for the product.
With regard to the definition of process unit for the SOCMI
standards, EPA wrote in the promulgation BID:
The definition was drafted by EPA to provide a common sense,
practical way to determine which equipment are included in an affected
facility. There are no specific physical boundaries or size criteria. The
definition instead depends upon several operational factors, including
2-33
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Notes
definition instead depends upon several operational factors, including
chemical produced and the configuration of the processing equipment
may be different for different producers of the same chemical, and,
therefore, it may be fairly site-specific. However, in practice, the
definition will implement the selection of a process unit basis as the
"source" covered by the standards.
Equipment
Each of these standards also define equipment, as follows:
Standard
SOCMI
Petroleum refinery
On-shore natural gas
processing plants
VHAP
Equipment Definition
Each pump, compressor, pressure relief device,
sampling connection system, open-ended valve
or line, valve,and flange or other connector in
VOC service and any devices or systems
required by this subpart.
Each valve, pump, pressure relief device,
sampling connection system, open-ended valve
or line, and flange or other connector in VOC
service. For the purposes of recordkeeping
and reporting only, compressors are considered
equipment.
Each pump, pressure relief devices, open-
ended valve or line, valve, compressor, and
flange that is in VOC service or in wet gas
service, and any device or system required by
this subpart.
Each pump, compressor, pressure relief device,
sampling connection system, open-ended valve
or line, valve, flange or other connector,
product accumulator vessel in VHAP service,
and any control devices or systems required by
this subpart.
The differences in the definitions of "equipment" result from
different ways to handle the identification of compressors as a separate
affected facility in the petroleum refinery and on-shore natural gas
processing plant standards and from the exemption of sampling
connection systems in on-shore natural gas processing plants from the
requirements of the SOCMI equipment leak standards.
2-34
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Notes
In VOC Service
The NSPS equipment leak standards apply to components that
are "in VOC service." The SOCMI equipment leak standards define
"in VOC service" as:
" ... means that the piece of equipment contains or contacts a
process fluid that is at least 10 percent VOC by weight."
This definition is retained in both the petroleum refinery and the on-
shore natural gas processing equipment leak standards. The 10 percent
VOC cutoff was selected by EPA to avoid covering those sources that
have only small amounts of ozone forming substances in the line.
The NSPS equipment leak standards differ depending on
whether the equipment in VOC service is in "gas/vapor service", in
"light liquid service" or in "heavy liquid service."
In Gas/Vapor Service
"In gas/vapor service" means that the piece of equipment
contains process fluid that is in the gaseous state at operating
conditions. Each of three NSPS standards use this definition.
In Lieht Liquid Service
. > -
Equipment is "in light liquid service" if the following conditions
apply:
1. The vapor pressure of one or more of components is
greater than 0.3 kPa at 20°C, or
2. The total concentration of the pure components having a
vapor pressure greater than 0.3 kPa at 20°C is equal to or
greater than 20 percent by weight and the fluid is a liquid at
operating conditions.
In addition to the above definition, the petroleum refinery and
on-shore natural gas processing plant standards allow an owner or
operator to define "in light liquid service" as follows:
2-35
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Notes
Equipment is in light liquid service if the percent
evaporated is greater than 10 percent at 150°C as
determined by ASTM Method D-86.
In Heavy Liquid Service
"In heavy liquid service" means that the piece of equipment is
not in gas/vapor service or in light liquid service. The on-shore natural
gas processing plant standard also allows the following definition for "in
heavy liquid service":
Equipment is in heavy liquid service of the weight percent
evaporated is 10 percent or less at 150°C as determined by
ASTM Method D-86.
Although not explicitly stated in the petroleum refinery standard, this
alternative definition can also be used for equipment located at
petroleum refineries.
Volatile Hazardous Air Pollutant (VHAP)
The NESHAP equipment leak standards apply to volatile
iazardous air pollutants (VHAP), which are defined in Subpart V (40
CFR Part 61) as:
" ... a substance regulated under this part for which a standard
for equipment leaks of the substance has been proposed and
promulgated. Benzene is a VHAP. Vinyl chloride is a VHAP."
In VHAP Service
"In VHAP service" means that a piece of equipment either
contains or contacts a fluid (liquid or gas) that is at least 10 percent by
weight a VHAP. This is the same basic definition for "in benzene
service" found in the benzene equipment leak standard (Subpart J, 40
CFR Part 61).
For vinyl chloride, the definition of "in vinyl chloride service"
means that a piece of equipment either contains or contacts a liquid
that is at least 10 percent vinyl chloride bv weight or a gas that is at
least 10 percent vinyl chloride bv volume. This definition is used in the
vinyl chloride standards (Subpart F, 40 CFR Part 61) rather than using
the "in VHAP service" found in Subpart V for determining the
applicability of Subpart F.
2-36
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Notes
Subpart V defines "in gas/vapor service" the same as the NSPS
equipment leak standards.
Subpart V defines "in liquid service" rather than "in light liquid
service" and "in heavy liquid service." "In liquid service" means that a
piece of equipment is not in gas/vapor service.
While these definitions are incorporated by reference by Subpart
J (benzene), Subpart F (vinyl chloride) does not differentiate between
"in gas/vapor service" and "in liquid service." Components "in vinyl
chloride service" are covered the same regardless of the fluid state.
One of the groups of equipment components by the equipment
leak standards are "flanges and other connectors."
Connector
In Subpart W (40 CFR Part 60), connector is defined as..."
flanged, screwed, welded, or other joined fittings used to connect two
pipe lines or a pipe line and a piece of process equipment.
In Subpart V (40 CFR Part 61), this definition is expanded by
the following phrase:
"For the purpose of reporting and recordkeeping, connector
means flanged fittings that are not covered by insulation or
other materials that-prevent location of the fittings."
The phrase was added September 30, 1986 (51 FR 34915). A
discussion of this is found in Lecture 8.
Product Accumulator Vessel
"Product accumulator vessel" means any distillate receiver,
bottoms receiver, surge control vessel, or product separator in VHAP
service that is vented to atmosphere either directly or through a
vacuum-producing system. A product accumulator vessel is in VHAP
service if the liquid or the vapor in the vessel is at least 10 percent by
weight VHAP.
Only Subpart V defines product accumulator vessel and only
Subpart J applies to product accumulator vessels. There have been a
number of questions raised concerning the application of this definition.
Lecture 8 presents some additional clarifications.
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Notes
LOCATING THE STANDARDS
Slide 2-15
We now turn to where one can find the individual equipment
leak regulations.
NSPSs Slide 2-16
The three NSPSs are found in Part 60 of Title 40 of the Code of
Federal Regulations. This is written as 40 CFR Part 60. Title 40
contains Federal regulations pertaining to the protection of the
environment. Part 60 contains the standards of performance for new
stationary sources. Within Part 60 there are subparts, which contain
the specific regulations for new stationary sources.
The SOCMI equipment leak standards are found in Subpart W
of 40 CFR Part 60. Sections (§) of this standard are found in §60.480
through §60.489.
The petroleum refinery equipment leak standards are found in
Subpart GGG of 40 CFR Part 60, and are found in §60.590 through
§60.593.
The on-shore natural gas processing plants equipment leak
standards are found in Subpart KKK of 40 CFR Part 60, and are found
in §60.630 through §60.636.
The dates shown in Slide 2-16 are those dates when the
regulations were initially proposed.
NESHAPs Slide 2-17
The three NESHAP standards are found in Part 61 of Title 40
of the Code of Federal Regulations (i.e., in 40 CFR Part 61). Part 61
contains the national emission standards for hazardous air pollutants.
Subpart V of 40 CFR Part 61 contains the national emission
standard for equipment leaks for volatile hazardous air pollutants
(VHAPs). This subpart contains the "generic" provisions and standards
that apply to benzene and vinyl chloride sources, as incorporated by
reference in the two subparts in 40 CFR 61 that apply specifically to
these two pollutants. This subpart was added to the regulations on
June 6, 1984.
Subpart J of 40 CFR Part 61 specifies the national emission
standard for equipment leaks of benzene, and basically incorporates
2-38
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Notes
Subpart V as its standards. Subpart J was added at the same as Subpart V
(June 6, 1984). Subpart J is found in §61.110 through §61.112 (§61.113 -
§61.119 are reserved).
Subpart F of 40 CFR Part 61 contains various standards for vinyl
chloride, not just equipment leak standards (§61.60 through §61.71).
Equipment leak standards are found in §61.65(b). The vinyl chloride
standards were added in 1976. At that time, some fugitive emission
sources were covered. Section 61.65 was revised at a later date to
incorporate the standards found in Subpart V (40 CFR Part 61). The most
recent correction was made on July 10, 1990.
APPLICABILITY OF THE STANDARDS Slide 218
This pan of the lecture reviews the applicability of the equipment
leak regulations. As noted earlier, new source performance standards
apply to newly constructed sources and only to existing sources when they
are modified or reconstructed. Thus, NSPSs have applicability dates to
identify when the standards become effective and thereby distinguish
between new and existing sources. The applicability date is the date of
proposal. NESHAPs, on the other hand, apply to both existing and new
sources and thus do not need an applicability date to distinguish between
new and existing sources. Both NSPSs and NESHAPs become effective
upon promulgation. Slide 2-18
Each regulation also exempts certain sources, equipment, or
process units from the entire regulation or portions thereof. These are
identified for each regulation.
Subpart W - SOCMI Slide 2-19
Subpart VV of 44 CFR Part 60 applies to equipment leaks in the
Synthetic Organic Chemical Manufacturing Industry (SOCMI). The
industry is defined as the industry that produces, as intermediates or final
products, one or more of the chemicals listed in §60.489.
The standards apply to any affected facility that commences
construction or modification after January 5, 1981.
The SOCMI rule defines the affected facility as the "group of all
equipment...within a process unit."
2-39
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Notes
These equipment are covered if they are "in VOC service," which
means that the piece of equipment contains or contacts a process fluid that
is at least 10 percent VOC by weight.
The SOCMI rule identifies several exemptions:
1. Any affected facility that has the design capacity to produce
less than 1,000 megagrams per year is exempt from §60.482.
There are some process units (e.g., research and
developmental facilities) that have production rates so small
that their VOC emissions from equipment leaks are likely to
very small and, as a consequence, the cost to control these
emission would be unreasonably high. This lower production
rate cutoff was developed on the basis of cost and emission
reduction considerations. Explanation of their analysis is
found in Section 5.7 of the background information document
for the promulgated standards (EPA-450/3-80-033b).
2. If an affected facility produces heavy liquid chemicals only
from heavy liquid feed or raw materials, then it is exempt
from §60.482.
Based on data obtained in petroleum refinery studies,
equipment processing VOC with vapor pressures above
0.3 kPa leaked at significantly higher rates and frequencies
than equipment processing VOC with vapor pressure below
0.3 kPa. Therefore, EPA elected to exempt equipment
processing lower vapor pressure VOC substances from the
routine leak detection and repair requirements of the standards
(BID Vol. II, p. 5-21). Even though the standards do not
require monitoring equipment in heavy liquid service for
leaks, the standards require VOC leaks that are visually or
otherwise detected from these equipment to be repaired within
15 days if a leak is confirmed using Reference Method 21.
3. Any affected facility that produces beverage alcohol is exempt
from §60.482.
During the public comment period on the proposed rule, EPA
received comments from the beverage alcohol producers
saying that they should be exempt from coverage by the
standards because beer and whisky producers were exempted
from the priority list. The EPA concluded that process units
within beer and whisky plants that are producing fermented
2-40
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Notes
beverages solely for purposes of human consumption should
be exempt from the standards. However, any process unit
(e.g., a distillation train to produce industrial grade alcohols
from fermentation products) in beer and whisky plants that are
used to manufacture nonbeverage fermented products are
subject to the standards. (BID Vol. II, p. 1-12).
4. Any affected facility that has no equipment in VOC service is
exempt from §60.482.
The EPA believes it appropriate to grant an exemption to any
SOCMI unit that does not process VOC. A few SOCMI
process units may produce their products without the use of
VOC; however, these units are expected to be the exception
rather than rule. SOCMI units that do not process VOC
would not have any potential to emit VOC.
5. Equipment in vacuum service is excluded from the
requirements of §§60.482-2 to 60.482-10 if it is identified as
required in §60.486(e)(5).
In EPA's judgement, it is inappropriate to cover sources in
vacuum service because sources operating even at a slight
vacuum would have little if any potential to emit VOC.
"In vacuum service" means that equipment is operating with
an internal pressure which is at least 5 kPa below ambient
pressure.
Subpart GGG - Petroleum Refineries Slide 2-20
Subpart GGG of 40 CFR Part 60 applies to equipment leaks in
petroleum refineries. The standards apply to any affected facility that
commences construction or modification after January 4, 1983.
This NSPS specifies that affected facilities covered by the
equipment leak standards for the SOCMI (Subpart W) or on-shore natural
gas processing plants (Subpart KKK) are excluded from these standards.
Some refineries, for example, produce organic chemicals on the SOCMI
list. Because some refineries have sources of fugitive VOC emissions
(such as pumps and valves) involved in producing one or more SOCMI
chemicals, EPA believes that the SOCMI standards are appropriately
applied to process units in these refineries that produce these chemicals.
Therefore, to eliminate any potential redundancy or confusion, process
2-41
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Notes
units covered under the SOCMI standards are exempted from the refinery
standards.
The affected facilities for this NSPS are:
1. each compressor; and
2. the group of all the equipment (defined in §60.591) within a
process unit.
In selecting the affected facilities for petroleum refineries, EPA
considered, in part, selecting each equipment component (such as each
pump and each valve). If this definition were selected, situations would
arise in which replaced equipment components in existing process units
would be subject to the standards, while adjacent component would not be
subject to the standards. With such a mixture of new and existing
components, the effort to keep track of equipment components covered by
the standards and components not covered would be costly. Implementing
a leak detection and repair program for a very small proportion of all the
equipment components at a plant site would be too costly. Thus, this
definition was rejected except for compressors.
Relatively few compressors are located in petroleum refineries; in
fact, many process units do not contain compressors. When a compressor
is used in a process unit, it is designed for use only within that process
unit. In general, there are no spare compressors in petroleum refineries,
and compressors that are in place are readily identifiable. Thus, it would
not be costly to keep track of compressors covered by the standards and
those it covered. Based on these considerations, EPA selected the
equipment component as the affected facility. (For all other equipment,
the process unit is affected facility.)
The petroleum refinery NSPS allows owners or operators to define
"in light liquid" service as: "if the percent evaporated is greater than 10
percent at 150°C as determined by ASTM Method D-86..."
This NSPS also contain several exemptions.
1. As for the SOCMI, equipment in vacuum service are
exempted.
2. Compressors hi hydrogen service are exempted. The EPA
analyzed the cost of control of equipment that, based on
EPA's data, would be found in hydrogen service. This
analysis showed that emission reductions from compressors in
2^2
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Notes
hydrogen service could not be achieved at a reasonable cost.
Thus, EPA decided to exclude such compressors from the
standards.
3. These standards also exempt from §60.482-2 and §60.482-7
pumps in light liquid service and valves in gas/vapor service
and light liquid service within a process unit that is located in
the Alaskan North Slope. This exempts refineries located in
the North Slope of Alaskan from the routine leak detection
and repair requirements, but does not include an exemption
from the equipment requirements of the standards.
Commenters on the proposed standards identified several
unique aspects of refining in the North Slope of Alaska.
These were:
• the products are used locally;
• process units are totally enclosed because of the harsh
environment; thus present safety controls are adequate and
additional requirements are unwarranted;
• requiring rupture disks ahead of pressure relief devices
would compromise safety, especially under this application;
• repair labor is 2-'/2 to 4 times more costly; and
• control of VOC is of limited value in an attainment area,
especially in the arctic where cold ambient temperature, the
degree of isolation, and a low concentration of
photochemical precursors limit ozone formation.
The EPA considered these comments and acknowledged that
there are several unique aspects to refining in the North Slope
of Alaska. Accordingly, EPA concluded that the costs to
comply with the routine leak detection and repair requirements
may be unreasonable. These operations incur higher labor,
administrative, and support costs associated with leak detection
and repair programs, because (1) they are located at great
distances from major population centers, (2) they must
necessarily deal with the long term extremely low
temperatures of the arctic, and consequently (3) they must
provide extraordinary services for plant personnel. These
unique aspects make the cost of routine leak detection and
repair unreasonable.
2-43
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Notes
Subpart KKK - Onshore Natural Gas Processing Plants Slide 2-21
Subpart KKK of 40 CFR Part 60 applies to equipment leaks in the
natural gas industry. Only equipment that is located at on-shore natural
gas processing plants are covered. Pieces of equipment that are remotely
located (i.e., not located at an on-shore natural gas processing plant) are
not covered by this NSPS. The standards apply to any affected facility
that commences construction, reconstruction, or modification after January
20, 1984.
This NSPS specifies that affected facilities covered by the
equipment leak standards for the SOCMI (Subpart VV) or for petroleum
refineries (Subpart GGG) are excluded from these standards.
As for petroleum refineries, this NSPS identifies two affected
facilities:
1. each compressor in VOC service or in wet gas service, and
2. the group of all equipment except compressors defined in
§60.631) within a process unit.
"In wet gas service" means that a piece of equipment contains or
contacts the field gas before the extraction step.
At proposal, EPA defined "in VOC service" using a 1.0 weight
percent VOC limit (rather than 10 weight percent). The intent of using
the 1.0 weight percent VOC limit was to ensure that inlet (wet) gas
streams were subject to NSPS controls, since emissions can be reduced at
reasonable costs from inlet gases. However, based on comments received
on the proposed standards, EPA agreed that a 1.0 weight percent limit was
inappropriate for dry gas streams. Therefore, EPA selected a VOC
concentration limit of 10 weight percent was selected in the final rule for
the "in VOC service" definition and decided to include equipment in wet
gas service (except for wet gas reciprocating compressors) by covering
them as a class.
The on-shore natural gas process plant NSPS allows owners to use
alternative definitions for "in heavy liquid service" and "in light liquid
service." An owner or operator may define in heavy liquid service" as:
Equipment is in heavy liquid service if the weight percent
evaporated is 10 percent or less at 150 °C as determined by ASTM
Method D-86.
2-44
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Notes
An owner or operator may define "in light liquid service" as:
Equipment is in light liquid service if the weight percent
evaporated is greater than 10 percent at 150°C as determined by
ASTM Method D-86.
This NSPS generally requires owners and operators to follow the
provisions found in Subpart VV (Equipment Leaks for the SOCMI).
Exceptions are provided. These include:
1. Sampling connection system are exempt from §60.482-5,
Standards: Sampling connection systems.
2. Pumps in light liquid service, valves in gas/vapor service and
in light liquid service, and pressure relief devices in gas/vapor
service that are located at a nonfractionating plant with a
design capacity to process less than 10 million standard cubic
feet per day of field gas are exempt from the routine
monitoring requirements of §60.483-2(a)(l), §60.482-7(a), and
§60.633(b)(l).
Small, nonfractionating plants often operate unmanned or
without personnel having the ability necessary to cany out
responsibly a leak detection and repair program. In these
cases, central office personnel or an outside consultant would
be required to conduct leak detection and repair. The EPA
examined the additional costs that would be incurred in such
cases and the amount of resulting emission reduction. The
EPA judged the costs to change from reasonable to
unreasonable at plants having capacities between 5 and 10
million standard cubic feet per day. Therefore, EPA decided
to exempt any nonfractionating plant with a design capacity of
less than 10 million scfd of field gas from the routine
monitoring requirements for valves, pumps, and pressure
relief devices.
However, all fractionating plants, regardless of capacity, or
required to implement the routine monitoring requirements.
3. Pumps in light liquid service, valves in gas/vapor service and
in light liquid service, and pressure relief devices in gas/vapor
service within a process unit that is located in the Alaskan
North Slope are exempt from the routine monitoring
requirements of §60.482-2(a)(l), §60.482-7(a), as
§60.633(b)(l). •
2-45
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Notes
The EPA reviewed comments concerning natural gas plant
operations in the North Slope of Alaska and determined that
the costs to comply with certain aspects of the proposed
standards can be unreasonable. Leak detection and repair
programs incur higher labor, administrative, and support costs
at plants that are located at great distances from major
population centers and particularly those that experience
extremely low temperatures as in the arctic. Thus, EPA
decided to exempt plants located in the North Slope of Alaska
from the routine leak detection and repair requirements. The
EPA excluded these plants only from the routine leak
detection and repair requirements because the costs of the
other requirements are reasonable.
4. Reciprocating compressors in wet gas service are exempt from
the compressor control requirements of §60.482-3,
compressors.
At proposal, EPA exempted reciprocating compressors in wet
gas service only if they were located at a gas plant that did not
have an existing control device. The cost effectiveness of
controlling such compressors was high due to the cost of
installing and operating a control device. However, the cost
effectiveness of controlling wet gas reciprocating compressors
at plants with an existing control device ($1,700 per
megagram of VOC reduced) was considered reasonable, given
that the average cost effectiveness (combining cost-
effectiveness numbers for centrifugal and reciprocating
compressors) was estimated to be much lower ($460 per
megagram). However, since proposal, several industry
representatives commented that many gas plants, especially
small ones, will use reciprocating compressors almost
exclusively. For such plants, the compressor control cost
effectiveness would be essentially the same as the cost
effectiveness for controlling only wet gas reciprocating
compressors at plants with an existing control device (i.e.,
$1,700 per megagram). This cost effectiveness, when
considered representative of the overall compressor control
costs for small plants, was judged by EPA to be unreasonably
high. For this reason, EPA revised the standards to exempt
all wet gas reciprocating compressors. Reciprocating
compressors used in natural gas liquids (NGL) service and all
centrifugal compressors in wet gas or NGL service are still
required to be equipped with closed vent systems, however,
2-46
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Notes
because they can be controlled at a reasonable cost
effectiveness.
Subpart J - National Emission Standard for Equipment Leaks Slide 2-22
(Fugitive Emission Sources) of Benzene
The national emission standards for equipment leaks (fugitive
emission sources) of benzene apply to pumps, compressors, pressure relief
devices, sampling connection systems, open-ended values or lines, valves,
flanges, and other connectors that are intended to operate in benzene
service.
These standards apply to both new and existing sources. Thus,
unlike the NSPS, there is no initial applicability date separating new from
existing sources.
"In benzene service" means that a piece of equipment either
contains or contacts a fluid (liquid or gas) that is at least 10 percent
benzene by weight as determined according to the provisions of
§61.245(d). The provisions of §61.245(d) also specify how to determine
that a piece of equipment is not in benzene service.
The benzene equipment leak NESHAP contains several
exemptions.
1. Any equipment in benzene service that is located at a plant
site designed to produce or use less than 1,000 megagrams of
benzene per year is exempt from the requirements of §61.112,
Standards.
Comments received on the proposed standards requested
certain small-volume or intermittent benzene uses be exempt
from the standard. Because EPA believes it is reasonable to
exempt plants from the standard when the cost of the standard
is unreasonably high in comparison to the achieved emission
reduction, EPA determined a cutoff for exempting plants
based on a cost and emission reduction analysis. Based on
this analysis, EPA determined that the cost comply ing with the
standard is unreasonable for plants in which the benzene
emission reduction is about 4 megagrams per year. In order
to exclude plants on this basis, EPA selected a minimum
cutoff of 1,000 Mg/yr per plant site based on a benzene design
usage rate or throughput. It is expected that this cutoff will
exempt most research and development facilities and other
small-scale operations. For plants with a benzene design
2-47
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Notes
usage rate greater than 1,000 Mg/yr, the cost of the standard
is reasonable.
2. Any process unit that has no equipment is benzene service is
exempt from the requirements of §61.112.
3. Sources located in coke-by-product plants are exempt from the
standard.
4. Equipment that is in vacuum service is excluded from the
requirements of §61.242-2 to §61.242-11 if it is identified as
required in §61.246(e)(5).
Suboart F - National Emission Standard for Vinvl Chloride Slide 2-23A
Subpart F of 40 CFR Part 61, the vinyl chloride standards, affect
emissions from plants that produce ethylene dichloride, vinyl chloride, and
one or more polymers containing any fraction of polymerized vinyl
chloride. On January 9, 1985, EPA proposed to add vinyl chloride to the
list of substances covered by Subpart V, National Emission Standard for
Equipment Leaks (Fugitive Emission Sources) of 40 CFR Part 61. This
was promulgated on September 30, 1986.
Subjecting facilities that had been already controlled by Subpart F
to the requirements of Subpart V substantively affected only valves and
flanges in vinyl chloride service because all other equipment in vinyl
chloride were already required by Subpart F to comply with equipment
and work practice standards consistent with those in Subpart V. Thus, the
primary effect was to require a specific monitoring schedule, leak
definition, and repair provisions for valves and flanges in vinyl chloride
service.
Like the other standards, Subpart F contains several exemptions
affecting equipment subject to the fugitive emission standards.
1. Subpart F does not apply to equipment used in research and
development if the reactor used to polymerize the vinyl
chloride processed in the equipment has a capacity of no more
than 0.19 m3 (50 gallons).
2. Equipment used in research and development are exempted Slide 2-23B
from some of Subpart F if the reactor used to polymerize the
vinyl chloride processed in the equipment has a capacity of
greater .than 0.19 m3 (50 gallons) and less than 4.07 m3 (1,075
2-48
-------
Notes
gallons). This includes exemption from §61.65, which
contains the standards for fugitive emission sources.
Sections of Subpart F that remain applicable are:
61.61, which contains the definitions,
61.64(a)(l), (b), (c), (d), which include some of the
standards for polyvinyl chloride plant reactors; strippers;
mixing; weighing, and holding containers; and monomer
recovery systems.
61.67, which contains emission test requirements.
61.68, which contains emission monitoring requirements.
61.69, which contains initial report requirements.
61.70, which contains reporting requirements.
61.71, which contains recordkeeping requirements.
3. Equipment in vacuum service is exempt.
4. Any process unit in which the percentage of leaking valves is
demonstrated to be less than 2.0 percent is exempt from the
following sections of Subpart V (40 CFR Part 61):
- 61.242-l(d), which requires each piece of equipment to be
marked in such a manner that it can be readily distinguished
from other pieces of equipment.
61.242-7(a), (b), and (c), of the standards for valves,
covering monitoring period and method to be used, leak
definition, and skip period.
- 61.246, which contains recordkeeping requirements.
- 61.247, which contains reporting requirements.
Such process units are still subject to the reporting and
recordkeeping requirements found specifically in Subpart F.
COMPONENT IDENTIFICATION Slide 2-24
In order to comply with the various equipment leak standards, an
owner or operator needs to be able to locate and identify components
subject to the standards. A number of such needs are identified in the
next slide.
2-49
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Notes
Identification Number Slide 2-25
Each component needs an identification (id) number. The id
number is used to comply with various recordkeeping and reporting
requirements. For example, the id number of each component that is
found to be leaking is recorded in a log. In addition, a list of the id
numbers of all equipment subject to the standards are to be recorded in a
log. Lists of identification numbers are also required for (1) equipment in
vacuum service, (2) valves designated as unsafe-to-monitor, (3) valves
designated as difficult-to-monitor, and (4) pressure relief devices required
to comply with §60.482-4.
Affected Facility
For the NSPS equipment leak standards, components are only
subject to the standards if they are located in an affected facility.
Therefore, it is important to identify the location of each component with
regard to the process unit it is in and whether that process unit is an
affected facility. For the NESHAP equipment leak standards, individual
components are exempt from the standards if located in process units that
have less than 2 percent of the valves leaking. Thus, it can be important
to locate the equipment in VHAP service to determine whether they can
be exempted.
Component Type
The standards have different requirements (e.g.., monitoring
intervals) depending on the type of component. Thus, the component type
needs to be identified.
Component Location
Many plants are large, containing many components. Locating a
specific component that is to be repaired can be difficult. Thus,
identifying the component location (where is it exactly in the plant) can
facilitate compliance with the standards.
2-50
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Notes
Fluid State
The standards also have different requirements depending on the
fluid state of the component. Thus, it is important to identify whether the
component is in gas/vapor service, in light liquid service, or in heavy
liquid service (if subject to an NSPS standard) or in VHAP service (if
subject to a NESHAP standard).
Mark Each Component
Under Subpart V [§61.241-1 (d)], each piece of equipment to which this
subpart applies to be marked in such a manner that it can be distinguished
readily from other pieces of equipment.
Percent VHAP
Under Subpart V, each piece of equipment within a process unit
that can conceivably contain equipment in VHAP service is presumed to
be VHAP service unless an owner or operator demonstrates that the price
of equipment is not in VHAP service. A piece of equipment is considered
to be not in VHAP service if the percent VHAP content can be reasonably
expected never to exceed 10 percent by weight. Thus, for these
components, it is important to identify the percent (%) VHAP.
THE STANDARDS IN DETAIL
This part of the lecture looks at the specific equipment leak
standards. The work practice standards (leak detections and repair
programs) are covered first. Then the equipment and performance
standards are discussed. This section concludes with a discussion on
equivalent means of emission limitations.
Leak Detection and Repair Slide 2-26
There are two phases to leak detection and repair (LDAR) Slide 2-27
programs. The first phase involves monitoring potential fugitive emission
sources within a process unit to detect equipment leaks of VOC. After
detection of the leak, the second phase involves the repair or replacement
of the fugitive emission source.
The level of emission reduction achieved by a LDAR program is Slide 2-28
affected by several factors. The three main factors are the monitoring
interval, leak definition, and repair interval. Training and diligence of
personnel conducting the program, repair methods attempted, and other
2-51
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Notes
site-specific factors may also influence the level of emission reduction
achievable; however these factors are less quantifiable than the three main
factors.
Monitoring Interval
The monitoring interval is the frequency at which individual
component monitoring is conducted. Pumps and valves are to monitored
once a month. For valves, the monitoring interval may be increased to
once every quarter for each valve that is found not to be leaking for two
successive months. For pumps, the LDAR program also specifies a
weekly visual inspection for indications of liquids dripping from the pump
seal.
Leak Definition
The leak definition is the VOC (or VHAP) concentration observed
during monitoring that defines leaking sources that require repair. Two
primary factors affected the selection of the leak definition. These factors
were: (1) the percent total mass emissions that can potentially be
controlled by the LDAR program and (2) the ability to repair the leaking
components. The leak definition selected for leak detection monitoring is
10,000 ppm.
Repair Interval
The repair interval is defined as the length of tune allowed between
the detection of a leak and repair of the leak. For each component, when
a leak is detected it is required to be repaired as soon as practicable, but
not later than 15 calendar days after it is detected except if the conditions
described under "Delay of repair" are met.
For each component, the first attempt at repair is to be made no Slide 2-29
later than 5 calendar days after each leak is detected For valves, first
attempts at repair include, but are not limited to, the following best
practices where practicable:
• tightening of bonnet bolts;
• replacement of bonnet bolts;
• tightening of packing gland nuts; and
• injection of lubricant into lubricated packing.
The standards do not identify similar first attempt repair practices
for the other components.
2-52
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Notes
Delay of Repair Slide 2-30
The EPA recognized that repair of leaking equipment may need to
be delayed for technical reasons. Thus both Subpart VV and Subpart V
identify circumstances under which repairs may be delayed. These
circumstances are identified below.
1. Delays of repair of equipment for which leaks have been
detected are allowed if the repair is technically infeasible
without a process unit shutdown. An example of such a
situation would be a leaking valve that could not be isolated
from the process stream and requires complete replacement or
replacement of internal parts. When a valve cannot be
physically isolated from the process stream, the process unit
must be shutdown to effect certain repairs on the valve. Thus,
because EPA believes shutdown to effect repair of valves is
unreasonable, EPA allows delay of repair when repair is
infeasible without a process unit shutdown.
2. Delay of repair equipment is allowed for equipment which is
isolated from the process and does not remain in VOC (or
VHAP) service. This typically applies to spare equipment that
is out of service. Delay of repair is not allowed for spare
equipment that is pressurized and prepared to be placed on-
line; such equipment is considered to be in (VOC or VHAP)
service.
3. Delay of repair for valves is allowed if the emissions of Slide 2-31
purged material resulting from the immediate repair are
greater than the fugitive emissions likely to result from the
delay and, when repair procedures are affected, the purged
material is collected and destroyed or recovered in a control
device complying with §60.482-10 or §60.242-11, as
applicable.
4. Delay of repair beyond a process unit shutdown is allowed for
valves, if three conditions are met:
- valve assembly replacement is necessary during the process
unit shutdown;
- valve assembly supplies have been depleted; and
- valve assembly supplies had been sufficiently stocked before
the supplies were depleted.
2-53
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Notes
Delay of repair beyond the next process unit shutdown is not
allowed unless the next process unit shutdown occurs sooner
than 6 months after the first process unit shutdown.
5. Delay of repair for pumps is allowed if repairs requires the Slide 2-32
use of a dual mechanical seal system that includes a barrier
fluid system and repair is completed as soon as practicable,
but not later than 6 months after the leak was detected.
Subpart F (vinyl chloride) basically adopts the same LDAR
requirements as identified in Subpart V for like components. The
differences are as follows:
1. A reliable and accurate vinyl chloride monitoring system shall
be operated for detection of major leaks and identification of
the general area of the plant where a leak is located.
2. The monthly monitoring requirements for valves are not
applicable to any process unit in which the percentage of
leaking valves is demonstrated to be less than 2.0 percent.
The calculation of this percentage is based, in part, on the
monitoring of a minimum of 200 valves or 90 percent of the
total valves in a process unit, whichever is less.
As noted earlier in this lecture, LDAR programs affect valves and Slide 2-33
pumps. In addition, other components have LDAR programs. Each of
these components are discussed in more detail below.
Valve LDAR Programs
There are basically four categories of valves in Subpart W to
which monitoring requirements apply. These are:
1. valves in gas/vapor or light liquid service or VHAP service;
2. valves demonstrated to be difficult-to-monitor;
3. valves demonstrated to be unsafe-to-monitor; and
4. valves in heavy liquid service.
The first three categories of valves are discussed first. Valves in Slide 2-34
heavy liquid service is discussed later.
2-54
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Notes
Valves in Gas/Vapor or Light Liquid or VHAP Service
For valves in gas/vapor or light liquid service, monthly monitoring
is required. Slides 2-35 through 2-37 illustrate two types of common
valves that would typically be subject to a LDAR program.
In selecting the monitoring interval, EPA noted that, in general: "
... more frequent monitoring would result in greater emissions reduction
because more frequent monitoring would allow leaks to be detected earlier
and thus allow more immediate repair."
The EPA considered monitoring intervals of less than one month
for these valves, but rejected shorter intervals. The EPA noted that the
large number of valves in certain SOCMI process units limits the practical
minimum for the monitoring intervals. For typical large process units, it
might take a two-man team more than one week to monitor all the valves.
Since some time is required to schedule repair after a leak is detected,
monitoring intervals less than one month could result in a situation where
a detected leak could not be repaired before the next monitoring was
required.
The EPA also considered a number of larger monitoring intervals.
These were annual; semiannual; quarterly; and quarterly with monthly
follow-up on leaking valves. These intervals, along with monthly
monitoring, were compared in terms of cost effectiveness and the emission
reduction achievable. Based on the analysis of the affect of monitoring
interval on costs and emission reduction, EPA determined that a monthly
monitoring program is to be used for these SOCMI standards. While less
frequent programs were found by EPA to be more cost-effective, EPA
determined that monthly monitoring also had reasonable cost effectiveness,
reasonable incremental cost effectiveness, and yielded the largest
emissions reduction of the programs examined.
At the National Air Pollution Control Techniques Advisory
Committee meeting (a public hearing held during the development of
standards), industry representatives argued that monitoring all valves
monthly would be an inefficient expense of time and manpower for valves
that leak infrequently or less often than others. If this is correct, more
monitoring effort should be expended on valves found leaking and less on
those found leaking infrequently. Therefore, for any valve that is not
found to be leaking for two successive months, the standards allow an
owner or operator to exclude such valves from monitoring until the first
month of the next quarterly period. Thereafter, such valves can be
monitored once every quarter until a leak is detected. If a valve leak is
detected, monthly monitoring of that valve is required until it has been
Slides 2-35 to
2-37
2-55
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Notes
shown leak free for two success months. At such time, quarterly
monitoring can be reinstituted.
Alternative Standards. In an effort to provide flexibility to the Slide 2-38
standards, EPA included two alternative standards for valves in gas/vapor
service, in light liquid service, and in VHAP service. Owners or
operators of affected facilities are allowed to identify and to elect and
comply with either of the alternative standards rather than the monthly
monitoring LDAR program. This allows owners and operators to tailor
the equipment leak requirements for these valves to their own operations.
Owners and operators are first required to carry out a monthly
monitoring program for at least one year. Then, a plant owner or
operator can elect to comply with one of the alternative standards based on
the information gathered during the one year's implementation of monthly
monitoring.
The first alternative standard for these valves limits to 2 percent Slide 2-39
the maximum percent of valves leaking within a process unit, determined
by a minimum of one performance test annually. This alternative was
provided to eliminate unreasonable costs. It provides an incentive to
maintain a good performance level and promotes low-leak unit design. .
The standard can be met by implementing any type of leak detection and
repair program and engineering controls chosen at the discretion of the
owner or operator.
A performance test to demonstrate compliance is required to be
conducted initially upon designation, annually, and at other times
requested by the Administrator. Performance tests are to be conducted by
monitoring all valves in gas/vapor service and all valves hi light liquid
service located in the affected facility within 1 week. If an instrument
reading of 10,000 ppm or greater is measured, a leak is detected. The
leak percentage is calculated by dividing the number of valves for which
leaks are detected by the number of valves in gas/vapor service and light
liquid service within the affected facility. Inaccessible valves that would
not be monitored on a routine basis are included in the performance test
and subsequent annual tests. The annual monitoring interval is not
considered burdensome for such valves. If the results of a performance
test show a percentage of valves leaking higher than 2 percent, the process
unit is not in compliance with the alternative standard.
Owners and operators electing to comply with this alternative
standard are required to notify the Administrator 90 days before
implementing this alternative standard. If an owner or operator
determines that he no longer wishes to comply with this alternative
2-56
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Notes
standard, he can submit a notification in writing to the Administrator
stating that he will comply with the work practice standard in §60.482-7
as appropriate.
The second alternative standard for these valves is a skip-period Slide 2-40
leak detection and repair program. Under the skip-period leak detection
provisions, an owner or operator can skip from routine monitoring
(monthly) to less frequent monitoring after completing a number of
successful sequential monitoring intervals. Considering a performance
level of less than 2 percent leaking and better than 90 percent certainty
that all periods have this performance level, the following sets of
conservative periods and fractions of periods skipped were determined:
• two consecutive quarterly periods achieved to skip to semi-
annual monitoring, and
• five consecutive quarterly periods achieved to skip to annual
monitoring.
This alternative requires that, if the percentage of valves leaking is
greater than 2.0, the monthly leak detection and repair program specified
in §60.482-7 or §61.242-7, as appropriate, must be reinstituted. This
does not preclude an owner or operator from electing to use this
alternative standard again. Compliance with this alternative work practice
standard would be determined by inspection and review of records.
As with the first alternative standard, owners and operators electing
to comply with this alternative standard are required to notify the
Administrator 90 days before implementing alternative standard. In
addition, the owner or operator must identify with which of the two skip
periods he or she is electing to comply.
Difficult-to-Monitor Valves Slide 2-41
Some valves are difficult to monitor because access to the valve is
restricted. The standards allow an annual leak detection and repair
program for valves that are difficult to monitor. Valves that are difficult
to monitor are defined as valves that would require elevating the
monitoring personnel more than two meters above any permanent available
support surface. The intent of this definition is that ladders should be
used to elevate monitoring personnel under safe conditions. However,
valves that cannot be safely monitored by, at least, the use of ladders are
classified as difficult to monitor, and, therefore, they may be monitored
annually rather than monthly.
2-57
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Notes
Difficult-to-monitor valves can be limited (but not necessarily
entirely eliminated) in new process units, but can not be eliminated in
existing process units. In new units, up to 3 percent of the valves can be
designated as difficult-to-monitor; all other valves are subject to the
monthly monitoring. This "less than 3 percent" allowance is not contained
in the NESHAP standards.
Unsafe-to-Monitor Valves
In .addition, some valves are "unsafe to monitor". Valves that are
unsafe to monitor cannot be eliminated in new or existing units. The
standards allow an owner or operator to submit a plan that defines a leak
detection and repair program conforming with the routine monitoring
requirements of the standards as much as possible given that monitoring
should not occur under unsafe conditions. Valves that are unsafe to
monitor are defined as those valves which could, based on the judgment of
the owner or operator, expose monitoring personnel to imminent hazards
from temperature, pressure, or explosive process conditions.
Pump LDAR Programs
For pumps in light liquid service, monthly monitoring is required
(unless an owner or operator elects to comply with the equipment
standards). Slides 2-44 and 2-45 illustrate two types of pumps that would
typically be subject to a LDAR program.
The EPA examined monthly and quarterly monitoring leak
detection and repair programs and the use of dual mechanical seals with
controlled degassing vents. Both LDAR programs are less costly than the
equipment installation. The lowest average and incremental costs per
megagram of VOC reduced were found to be associated with the monthly
LDAR program. The monthly LDAR program achieves greater emission
reduction than the quarterly LDAR program, but less than the installation
of the control equipment. The cost of the control equipment, however,
was found to be high. Because the incremental costs for this equipment
was considered to be unreasonably high in light of the resulting
incremental emission reductions, EPA selected monthly monitoring as the
basis for the standards.
In addition, each pump in light liquid service is to be checked by
visual inspection each calendar week for indications of liquids dripping
from the pump seal.
The LDAR requirements for pumps hi VHAP service are the same
as those for pumps in light liquid service under the NSPS standards. The
Slide 2-42
Slide 2-43
Slides 2-44 and
2-45
2-58
-------
Notes
In addition, each pump in light liquid service is to be checked by
visual inspection each calendar week for indications of liquids dripping
from the pump seal.
The LDAR requirements for pumps in VHAP service are the
same as those for pumps in light liquid service under the NSPS
standards. The NESHAP LDAR requirements, however, added a
provision whereby any pump that is located within the boundary of an
unmanned plant site is exempt from the weekly visual inspection
requirements and the daily requirement to check sensors, provided that
each pump is visually inspected as often as practicable and at least
monthly.
Other Equipment LDAR Programs
Pumps and valves in heavy liquid service, pressure relief devices Slide 2-46
in light liquid or heavy liquid service, and flanges and other connectors
are to be monitored within 5 days if evidence of a potential leak is
found by visual, audible, olfactory, or any other detection method. A
leak is considered detected if the monitoring shows a reading of 10,000
ppm or greater. These requirements also apply to NESHAP pressure
relief devices in liquid service and flanges and other connectors.
For pressure relief devices in gas/vapor service, the on-shore
natural gas processing plant standards allow an owner or operator to
monitor these components on a quarterly basis to determine whether
there is a leak, and defines a leak as a reading of 10,000 ppm or
greater. This differs from Subpart W, which required these
components to be operated with "no detectable emissions." (The
difference is due to the results of the cost and emission reduction
analyses for emission reduction alternatives at on-shore natural gas
processing plants). Both subparts require monitoring of the pressure
relief devices within 5 days after each pressure release.
After a pressure release, pressure relief devices located in a
non-fractionating plant that is monitored only by nonplant personnel
may be monitored the next time personnel are on site (instead of the 5
days noted above). However, these components must be monitored
within 30 days after a pressure release.
Exemptions from LDAR Programs
Pumps in light liquid service, valves in gas/vapor service, valves
in light liquid service, and pressure relief devices in gas/vapor service
are exempt from the routine LDAR requirements of §60.482-2(a)(l),
2-59
-------
Notes
§60.482-7(a) and §60.633(b)(l) if they are located (1) at a
nonfractionating plant with a design capacity to process less than 10
million scfd of field gas or (2) in process units located in the Alaskan
North Slope.
Equipment Design, and Operational Standards and Performance Slide 2-47
Standards
This part of the lecture focuses on the equipment, design, and
operational standards and performance standards associated with each
component. The components that have these standards are listed in Slide 2-48
Slide 2-48.
Equipment standards, for our purposes, refer to either: (1) the
design of the fugitive equipment, or control device; or (2) the physical
control specifications. Design standards include requirements for dual
mechanical seals; closed purge and vent systems; caps, blind flanges,
second valves, and control equipment specification associated with
flares and enclosed combustion devices. Included are operational
standards that specify how certain equipment is to be operated.
Performance standards, for our purposes, refer to: (1) no
detectable emissions, and (2) for control devices, percent reduction
efficiency. Annual monitoring is used for components subject to the
"no detectable emissions" requirement These components include
pumps, compressors, valves (those specifically designated for no
detectable emissions), and closed-vent systems for both NSPS and
NESHAP. As discussed earlier, "no detectable emissions" means
emissions are less than 500 ppm above background levels. These
components are to be tested for compliance with "no detectable
emissions" initially upon designation, annually, and at other times
requested by the Administrator. The longer interval reflects the
expectation that leaks do not occur in leakless equipment
Other monitoring intervals are specified in the rules. Pressure
relief devices in gas/vapor service (NSPS and NESHAP) are to be
monitored as soon as practicable, but no later than 5 calendar days
after a pressure release, to determine whether the device has been
returned to a condition of "no detectable emissions."
Pnmps Slide 2-49
In addition to the LDAR program, the regulations identify both
equipment, design, and operation standards and performance
standards. The wording of .the regulations is such that a pump does
2-60
-------
Notes
not need to comply with the LDAR program if it meets one of three
conditions.
Dual Mechanical Seal System. A pump in light liquid service is
exempt from the LDAR program if it is equipped with a dual
mechanical seal system that includes a barrier fluid system. (This does
not exempt such pumps from the weekly visual inspection for
indications of liquids dripping from the pump seals). This equipment
standard was the original standard proposed for these pumps.
The regulation identifies three conditions, one of which must be
met in order for pumps with a dual mechanical seal system that
includes a barrier fluid system to be exempt from the LDAR program.
These are:
1. Operated with the barrier fluid at a pressure that is at all Slide 2-50
times greater than the pump stuffing pressure.
(VOC leakage to the atmosphere will not occur if the
barrier fluid is maintained at a pressure greater than the
stuffing box pressure, because all leaks would be inward,
into the process fluid).
2. Equipped with a barrier fluid degassing reservoir that is
connected by a closed vent system to a control device.
3. Equipped with a system that purges the barrier fluid into a
process stream with zero VOC (or VHAP) emissions to the
atmosphere.
(If the stuffing box pressure is greater than the barrier fluid
pressure, the barrier fluid between the two seals collects
leakage from the inner seal. The VOC collected by the
barrier fluid can be controlled by connecting the barrier
fluid reservoir to a control device with a closed vent system
or by returning it to the process).
When equipment standards are established, Section lll(h) of
the Clean Air Act requires that requirements be also established to
ensure the proper operating and maintenance of the equipment The
standards for pumps therefore require the following:
The barrier fluid system is to be either in heavy liquid Slide 2-51
service or not in VOC service.
2-61
-------
Notes
(The use of light liquid VOC as a barrier fluid could result
in emissions of VOC of the same magnitude as those that
would occur if product VOC were allowed to leak past the
seals.)
Each barrier fluid system is to be equipped with a sensor
that will detect failure of the seal system, the barrier fluid
system, or both. The regulations allow the owner/operator
to determine the criterion to be used to indicate failure.
(Such a system would reveal any catastrophic failure of the
inner or outer seal or barrier fluid system).
Each sensor is to be checked daily or is to be equipped with
an audible alarm.
When a leak is detected (either by visual inspection or by
the sensor indicating a failure), it is to be repaired as soon
as practicable, but no later that 15 days after it is detected,
except as provided by the "Delay of Repair" provisions. A
first attempt at repair is to take place no later than 5 days
after each leak is detected.
Slide 2-53 illustrates a typical double mechanical seal on a
pump.
No Detectable Emissions. Pumps do not need to comply with
the LDAR program or dual mechanical seal system requirement if it is
designated for no detectable emissions, which is indicated by an
instrument reading of less than 500 ppm above background. However,
any pump that is designated for "no detectable emissions" can not have
an externally actuated shaft that penetrates the pump housing. Slides
2-55 through 2-57 illustrate several types of pumps that do not have an
externally actuated shaft penetrating the pump housing. These pumps
are candidates for designation for "no detectable emissions."
Pumps designated for "no detectable emissions are to be (1)
demonstrated to be operating with no detectable emissions as indicated
by an instrument reading of less than 500 ppm above background and
(2) tested for compliance with the less-than-500 ppm above background
reading initially upon its designation, annually, and at other times as
requested by the Administrator.
Slide 2-52
Slide 2-53
Slide 2-54
Slides 2-55 to
2-57
2-62
-------
Notes
Closed Vent System and Control Device. If a pump is equipped Slide 2-58
with a closed vent system capable of capturing and transporting any
leakage from the seal or seals to a control device that complies with
the requirements identified in the rule for such control device, it is
exempt from the requirements identified in the above paragraphs.
Exemptions. Subparts GGG and KKK exempt pumps in light
liquid service located in process units that are located in the Alaskan
North Slope from the routine leak detection and repair requirements,
but not the equipment standards.
Subpart KKK also exempts these pumps if they are located in
nonfractionating plants with a design capacity of less than 10 million
standard cubic feet per day from the routine leak detection and repair
requirements but not the equipment standards.
Compressors Slide 2-59
The basic requirements for compressors are found in §60.482-3
of Subpart W (40 CFR Part 60) and §61.242-3 of Subpart V (40 CFR
Part 61). Compressors may comply with either an equipment standard
or a performance standard The equipment standard requires either:
1. A seal system that includes a barrier fluid system and that
prevents leakage of VOC to the atmosphere; or
2. A closed vent system and control device.
Seal System with Barrier Fluid System. As for pumps in light Slide 2-60
liquid service, there are three conditions associated with this equipment
standard, any one of which must be met These are:
1. Operated with the barrier fluid at a pressure that is at all
times greater than the compressor stuffing box pressure; or
2. Equipped with a barrier fluid system that is connected by a
closed vent system to a control device that meets the
requirements specified in the rule for such control device;
or
3. Equipped with a system that purges the barrier fluid into a
process stream with zero VOC (or VHAP) emissions to the
atmosphere
2-63
-------
Notes
Also, as for pumps in light liquid service, there are several
operation- and maintenance-type conditions that are to be met These
are:
The barrier fluid system is to be either in heavy liquid Slide 2-61
service or not in VOC (or VHAP) service.
Each barrier fluid system is to be equipped with a sensor
that will detect failure of the seal system, the barrier fluid
system, or both.
Each sensor is to be checked daily or is to be equipped with
an audible alarm. (Subpart V exempts compressors located
is unmanned plant sites from this particular requirement)
When a leak is detected (based on the sensor indicating
failure), it is to be repaired as soon as practicable, but no
later than 15 days after it is detected, except as provided by
the "Delay of Repair" provisions. A first attempt at repair
is to take place no later than 5 days after each leak is
detected.
Note that the standards for compressors do not require weekly
visual inspection for indications of a potential leak as was required for
pumps in light liquid service.
Closed Vent System and Control Device. A compressor does Slide 2-62
not need to comply with the above equipment standard if it is equipped
with a closed vent system capable of capturing and transporting any
leakage from the seal to a control device that complies with the
requirements specified in the rules for that control device. Slide 2-63 Slide 2-63
illustrates a liquid-film compressor shaft seal This type of seal does
not eliminate VOC leakage, and thus a closed-vent system to a control
device is likely to be needed.
No Detectable Emissions. Some compressors may be designated Slide 2-64
for "no detectable emissions." Such compressors do not need to
comply with either equipment standard described above. Compressors
that are designated for "no detectable emissions" are to comply with
this performance standard by:
1. demonstrating that it is operating with no detectable
emissions, as indicated by an instrument reading of less than
500 ppm above background; and
2-64
-------
Notes
2. testing for compliance with the less-than-500 ppm above
background reading initially upon designation, annually
thereafter, and at other times as requested by the
Administrator.
Exemptions. Both Subparts W and GGG exempt reciprocating
compressors from the equipment standards for compressors, if the only
means for bringing the compressor into compliance with §60.482-3(a)
through (e) and (h) are through either the recasting of the distance
piece or the replacement of the compressor. Subpart GGG also has an
exemption for compressors in hydrogen service.
Subpart KKK exempts reciprocating compressors in wet gas
service from all of §60.482-3, but requires reciprocating compressors in
natural gas liquid service to comply with §60.482-3.
Subparts V, F, and J do not exclude any type of compressor
from compliance; both rotating and reciprocating compressors are
covered. The monitoring requirements for compressors in VHAP
service are the same as those for compressors in VOC service under
the NSPS standards, except that for compressors located within the
boundary of an unmanned plant site each sensor required does not
need to be checked daily or equipped with an audible alarm.
Pressure Relief Devices in Gas/Vapor Service
The standards for pressure relief devices in gas/vapor service
requires them either to operate with no detectable emissions or to be
equipped with a closed vent system and control device. As for pumps
and compressors, "no detectable emissions" refers to an instrument
reading of less than 500 ppm above background. Pressure relief
devices complying with the no detectable emissions standard are to be
returned to that condition within 5 calendar days after each pressure
release, except as provided in the "Delay of Repair" provisions. The
standards also require that the pressure relief device be monitored not
later than 5 calendar days after a pressure release to confirm the
condition of no detectable emissions has been achieved.
The pressure relief devices do not need to comply with the "no
detectable emissions" standard if they are equipped with a closed-vent
system capable of capturing and transporting leakage from the pressure
relief device to a control device that meets the requirements for that
control device.
Slides 2-65
through
2-67
Slide 2-68
Slide 2-69
2-65
-------
Notes
All of the subparts cover all pressure relief devices in gas/vapor
service with one exception. Subpart KKK exempts these devices from
the routine monitoring requirements if they are in process units located
in the Alaskan North Slope.
Sampling Connection Systems Slide 2-70
Sampling connection systems are to be equipped with a closed
purge system or a closed vent system. Each closed-purge system or
closed-vent system is to do one of the following:
return the purged process fluid directly into the process line
with zero VOC or (VHAP) emissions to the atmosphere; or
collect and recycle the purged process fluid with zero VOC
(or VHAP) emissions; or
be designed and operated to capture and transport all the
purged process fluid to a control device that complies with
the requirements for that control device.
Slide 2-71 illustrates two closed-loop sampling systems. Slide 2-71
Subparts W, GGG, V, and J exempt in-situ sampling systems,
while Subpart KKK exempts all sampling connection systems.
Open-Ended Valves or T ines Slide 2-72
Like sampling connection systems, open-ended valves or lines
only have equipment standards including operational requirements;
there are no performance or work practice standards. Open-ended
valves or lines are to be equipped with a cap, blind flange, plug, or
second valve. The cap, blind flange, plug, or second valve is to seal the
open end at all times except during operations requiring process fluid
flow through the valve or line.
The cap, blind flange, plug, or second valve is to seal the open
end at all times except during operations requiring process fluid flow
through the open-ended line or valve.
If a second valve is used, the open-ended line or valve is to be Slide 2-73
operated so that the valve on the process fluid end is closed before the
second valve is closed.
2-66
-------
Notes
If a double block-and-bleed system is being used, the bleed valve
or line is allowed to remain open during operations that require
venting the line between the block valves. At all other times, the open
end of the bleed valve or line is to be sealed (again, except during
operations requiring process fluid flow through the open-ended line or
valve).
Process Valves Slide 2-74
Leak detection and repair programs are the primary standards
for controlling equipment leak emissions from process valves. The
standards allow these valves to comply with the performance standard
of "no detectable emissions." A valve may be designated for "no
detectable emissions" only if it does not have an external actuating
mechanism in contact with the process fluid. As for the other
equipment so designated, "no detectable emissions" refers to an Slide 2-75
instrument reading of less than 500 ppm above background. Valves
designated for "no detectable emissions" are to be operated with
emissions less than 500 ppm above background and to be tested for
compliance with the less-than-500 ppm above background reading
initially upon designation, annually thereafter, and at other times as
requested by the Administrator. Slides 2-76 and 2-77 illustrate two Slides 2-76
types of diaphragm seals. These types of seals would allow these valves and 2-77
to be designated for "no detectable emissions" as there is no external
actuating mechanism in contact with the process fluid. Similarly, sealed
bellows valves (see Slide 2-78) do not have a stem or gland and, Slide 2-78
therefore, are not prone to leak. These valves can also be designated
for "no detectable emissions."
Flanges and Other Connectors
Flanges and other connectors are subject to the "no evidence of
a potential leak" work practice standard, which was discussed earlier.
There are no equipment or performance standards for these
components.
Product Accumulator Vessels Slide 2-79
These vessels (NESHAP only) are subject to equipment
standards only; there are no performance or work practice standards.
The equipment standards require product accumulator vessels to be
equipped with a closed-vent system capable of capturing and
transporting any leakage from the vessel to a control device that meets
the requirements for that control device.
2-67
-------
Notes
Agitators Slide 2-80
Vinyl chloride emissions from seals on all agitators in vinyl
chloride service are to be minimized by installing agitators with double
mechanical seals or equivalent. If double mechanical seals are used,
then one of the following is required:
maintaining the pressure between the two seals so that any
leak that occurs is into the agitated vessel; or
ducting any vinyl chloride between the two seals through a
control system from which the vinyl chloride in the exhaust
gases does not exceed 10 ppm; or
equivalent.
Qosed Vent Systems and Control Devices
As with the various individual equipment components, the
closed vent systems and control devices that can be used to comply
with the standards also have equipment and performance standards.
Qosed Vent Systems. Qosed vent systems are to be designed Slide 2-81
for and operated with no detectable emissions. They are to be
monitored at startup, annually thereafter, and at other times as may be
requested by the Administrator. In addition, closed vent systems are to
be operated at all times when emissions may be vented to them.
Control Devices. Control devices identified are vapor recovery Slide 2-82
systems, enclosed combustion devices, and flares. Control devices are
to be monitored to ensure proper maintenance and operation. The Slide 2-83
parameters to be monitored are selected by the plant owner or
operator. The regulations also require that control devices are
operated at all times when emissions may be vented to them.
Vapor recovery systems (such as condensers and adsorbers) are
to be designed and operated to recover the organic vapors vented to
them with an efficiency of 95 percent or greater.
Enclosed combustion devices are required to reduce emissions
by at least 95 percent or to be operated with a minimum residence
time at a minimum temperature. For enclosed combustion devices
used to comply with the NSPS, minimum residence time is 0.75 seconds
and the minimum temperature is 816°C. For enclosed combustion
devices used to comply with the NESHAP, these values are 0.5 seconds
2-68
-------
Notes
and 760°C, respectively The differences in the residence times and
temperatures reflects, in part, continuing research and conclusions as to
the minimum residence time and temperature required to ensure that
95 percent (or higher) reduction efficiencies are achieved.
Subpart W states that flares used to comply with this subpart Slide 2-84
are to comply with the requirements §60.18. Section 60.18 requires the
use of a steam-assisted, air-assisted, or nonassisted flare. These flares
are to be operated with no visible emissions, except for periods not to
exceed a total of 5 minutes during any 2 consecutive hours. They are
to be operated with a flame present at all times. The presence of a
flare pilot flame is to be monitored using a thermocouple or any other
equivalent device to detect the presence of a flame. In addition,
owners or operators are to monitor the flares to ensure that they are
operated and maintained in conformance with their designs. Finally,
Section 60.18 identifies minimum net heating values and maximum exit
velocities for the flares.
Subpart V incorporates these same provisions. There may be
some discrepancies in the methods identified in Subpart V for
calculating net heating values or exit velocities with those in §60.18.
Where such discrepancies are found, the methods identified in §60.18
should be used.
Slide 2-85 illustrates a simplified closed-vent system with a dual Slide 2-85
flare system.
Equivalent Means of Emission Limitations Slide 2-86
Under the standards, any owner or operator of an affected
facility can request that the Administrator determine the equivalence of
any alternative means of emission limitation to the equipment, design,
operational, and work practice requirements of the standards.
Excluded from this provision are the standards for pressure relief
devices in gas/vapor service and the standards for delay of repair. The
equivalent means of emission limitations are the same for both NSPSs
(§60.484) and NESHAPs (§61.244).
Each owner or operator subject to the provisions of these Slide 2-87
subparts may apply to the Administrator for determination of
equivalence for any means of emission limitation that achieves a
reduction in VOC emissions of at least equivalent to the reduction in
emissions of VOC achieved by the controls required in these subparts.
In addition, manufacturers of equipment used to control equipment
leaks of VOC can apply to the Administrator for determination of
2-69
-------
Notes
equivalence for any equivalent means of limitation that achieves a
reduction in VOC emissions achieved by the equipment, design, and
operational requirements of these subparts.
After a request for determination of equivalence is received, the
Administrator publishes a notice in the Federal Register and provides
an opportunity for a public hearing if the Administrator judges that the
request may be approved. After the notice has been published and an
opportunity for a public hearing provide, the Administrator determines
the equivalence of the means of emission limitation. (Guidelines used
to make this determination are outlined below.) The determination is
then published in the Federal Register. Any approved equivalent
means of emission limitations constitute a required work practice,
equipment, design, or operational standard within the meaning of
Section lll(h)(l) of the Clean Air Act.
The standards identify guidelines for determining equivalence.
For determining equivalence to the equipment design, and operational
requirements, the following guidelines are specified:
Each owner or operator or equipment manufacturer is
responsible for collecting and verifying test data to
demonstrate equivalence of means of emission limitation.
Sufficient information needs to be collected to demonstrate
that the alternative control technique is equivalent to the
control technique specified in the standards.
The Administrator then compares the test data submitted
by the owner, operator, or equipment manufacturer to the
test data for the equipment, design, and operational
requirements.
The Administrator is allowed to condition the approval of
equivalence on requirements that may be necessary to
ensure operation and maintenance to achieve the same
emission reduction as the equipment, design, and
operational requirements.
For determining equivalency with the required work practices.
the following guidelines are specified:
As above, each owner or operator is responsible for
collecting and verifying test data to demonstrate
equivalence of means of emission limitation.
2-70
-------
Notes
For each affected facility for which a determination of
equivalence is requested, the emission reduction achieved
by the required work practice is to be demonstrated.
Each owner or operator is to commit to work practice(s)
that provide for emission reductions equal to or greater
than the emission reductions achieved by the required work
practice.
The Administrator then compares the demonstrated
emission reduction for the equivalent means of emission
limitation to the demonstrated emission reduction for the
required work practice and will consider the commitment of
the owner or operator to work practices (as noted in the
above paragraph).
The Administrator may condition the approval of
equivalence or requirements that may be necessary to
ensure operation and maintenance to achieve the same
emission reduction as the required work practice.
If he or she desires, an owner or operator may offer a unique
approach to demonstrate the equivalence of any equivalent means of
emission limitation.
TEST METHODS AND PROCEDURES Slide 2-88
This section of the lecture outlines the requirements associated
with the test methods and procedures used to comply with the
standards. Each owner or operator subject to these standards are
required to comply with the test methods and procedure requirements
provided in these sections of the regulations. Slide 2-89 lists the areas Slide 2-89
covered by test methods and procedures, which are discussed briefly
below.
Monitoring Method
All monitoring for leaks is to be performed in accordance with
Reference Method 21. The test methods and procedures section
discusses some of the specifics in using Method 21. A detailed
discussion of Method 21 is presented in Lecture 6.
2-71
-------
Notes
In VOC (or VHAP) Service Presumption
One of the basic presumptions of the equipment leak standards
is that a piece of equipment is in VOC (or VHAP) service and, thus, is
subject to the standards. This presumption can be overcome by an
owner or operator demonstrating that the piece of equipment is not in
VOC (or VHAP) service.
In order for a piece of equipment to be considered not in VOC
(or VHAP) service, it must be determined that the percent VOC (or
VHAP) can be reasonably expected never to exceed 10 percent by
weight. For VOCs, the weight percent determination is to conform to
the general methods described in ASTM E-260, E-168, or E-169. For
VHAPs the weight percent determination is to conform to the general
method described in ASTM D-2267.
Subpart KKK extends this presumption to equipment in wet gas
service (i.e., each piece of equipment is presumed to be in VOC
service or in wet gas service). For a piece of equipment to be in wet
gas service, it must be determined that it contains or contacts the field
gas before the extraction step in the process. An owner or operator
must demonstrate otherwise to exclude equipment from the in-wet-gas-
service presumption.
In determining the weight percent VOC of the process fluid, an
owner or operator may exclude non-reactive organic compounds from
the total quantity of organics provided:
• the substances excluded are those considered to have
negligible reactivity by the Administrator, and
• the owner or operator demonstrates that the percent
organic content, excluding non-reactive organic compounds,
can be reasonably expected never to exceed 10 percent by
weight
An owner or operator may elect to use engineering judgment
rather than procedures outlined above to demonstrate that the weight
percent does not exceed 10 percent The rule requires that the
engineering judgment demonstrates that the VOC (or VHAP) content
clearly (emphasis added) does not exceed 10 percent by weight If
there is disagreement between EPA and an owner or operator about
whether the engineering judgement clearly demonstrates this, then the
procedures outlined above (use of the appropriate ASTM method) are
to be used to resolve the disagreement
2-72
-------
Notes
If an owner or operator determines that a piece of equipment is
in VOC (or VHAP) service, the determination can be revised only
after following the procedure associated with the ASTM methods;
engineering judgement cannot be used to revise the determination.
In Light Liquid Service Conditions
For the NSPSs, a distinction is made between equipment
according to the type of service. In this section of the rule, the
conditions for determining whether a piece of equipment is in light
liquid service are identified. In Subpart V, the conditions are:
• the vapor pressure of one or more of the components is
greater than 0.3 kPa at 20°C;
• the total concentration of the pure compounds have a
vapor pressure greater than 0.3 kPa at 20°C is equal to or
greater than 20 percent by weight; or
• the fluid is liquid at room temperature.
In making the above determination, vapor pressures may be
obtained from standard references or may be determined by ASTM
D-2879.
As noted earlier, Subparts KKK and GGG allow owners or
operators to use an alternative definition for in light liquid service. In
these two standards, a piece of equipment can be designated as being
in light liquid service if:
• the weight percent evaporated is greater than 10 percent at
150°C (as determined by ASTM Method D86).
Representative Samples
This part of the rules simply states that the samples taken in
conjunction with: (1) determining that a piece of equipment is not in
VOC (or VHAP) service, (2) determining whether a piece of
equipment is light liquid service, and (3) the heat content of the gas
shall be representative of the process fluid that is contained in or
contacts the equipment or the gas being combusted in a flare.
2-73
-------
Notes
Flares
Both Subpart W (40 CFR Part 60) and Subpart V (40 CFR
Part 61) identify certain requirements associated with the use of flares
in complying with these standards. These requirements include the use
of Reference Method 22 to determine compliance with the visible
emission provisions for flares and the monitoring of the presence of a
flare pilot flame using a thermocouple or any other equivalent device
to detect the presence of a flame. The requirements also include
calculation and sampling procedures for determining the heat content
and exit velocity. All of these requirements are also found in Section
60.18 of 40 CFR Part 60. Some discrepancies may be found in the
individual subparts when compared to Section 60.18. If so, the
procedures in Section 60.18 should be followed.
RECORDKEEPING AND REPORTING REQUIREMENTS
Recordkeeping and reporting requirements are included in
regulations to provide documentation for the assessment of compliance
with each type of standard (work practice, performance, equipment,
etc.). Review of these records and reports provide information for
enforcement personnel to assess implementation of the standards.
Compliance with the standards is determined, in general, by the
inspection and review of the records.
Slide 2-91 lists some of the records to be kept by the plant
owner or operator during activities associated with complying with the
standards. Slide 2-93 lists some of the reports an owner or operator is
required to submit Review of the submitted reports reduces, but does
not necessarily eliminate, the need for in-plant inspections. A detailed
discussion on the specific recordkeeping and reporting requirements is
found in Lecture 7.
Slides 2-90
through 2-93
2-74
-------
Notes
LECTURE 3
SUMMARY OF THE HAZARDOUS ORGANIC NESHAP (HON)
INTRODUCTION Notes
Existing regulations, adopted under sections 111 and 112 of the Slide 3-1
Clean Air Act and in State Implementation Plans (SIPs), have been
effective in heightening industry's awareness of the significance of
equipment leaks and in stimulating their control efforts. When these
rules were established, EPA estimated that emissions would be reduced
by between 60 and 70 percent, and that after control, leak frequencies
at applicable plants would be approximately 5 percent.
Since that time, data gathered on equipment leaks at some
selected chemical plants indicate that lower leak frequencies can be
achieved. Unfortunately, procedures specifying how low leak
frequencies could be obtained at all chemical plants were not included Slide 3-2
in the data. Consequently, EPA saw the need for a new regulatory
approach, but at the same time recognized that establishing a
regulation for such a broad and varied source category as chemical
production units would be difficult.
RULEMAKING PROCESS Slide 3.3
Accordingly, on April 25, 1989 (under 54 FR 17944), EPA
announced its intent to form an advisory committee to negotiate issues
leading to this new regulatory approach. On September 12, 1989, it
announced the formation of the Committee, under the Federal
Advisory Committee Act (54 FR 37725). During the course of the
following year, the Committee met periodically and successfully agreed
in principle to the provisions .and language of an equipment leak
regulation. EPA plans to propose this rule in early 1992 with
promulgation scheduled for fall 1992 as part of the hazardous organic
national emission standards for hazardous air pollutants (NESHAP).
Additionally, the proposed Hazardous Organic NESHAP, or HON, will
cover other emission points as well as equipment leaks; specifically,
storage and transfer points, process vents, and wastewater emissions.
Standards would apply to equipment in volatile hazardous air
pollutant (VHAP) service 300 or more hours per year associated with
any of the 453 processes listed in the regulation that make or use as a
3-1
-------
Notes
reactant one of the organic VHAPs listed in § XX.X8-1 of the
regulation (these VHAPs are also listed in Reference Volume 1-3.1).
Standards also apply to equipment handling specific chemicals
for a limited number of non-SOCMI processes (including benzene and
vinyl chloride) listed in the negotiated rule/
It is notable that petroleum refinery processes are not covered
by the HON. EPA plans to conduct a separate rulemaking for these
processes.
The equipment to be affected include valves, pumps, connectors,
compressors, pressure-relief devices, open-ended lines, sampling
connection systems, instrumentation systems, agitators, product
accumulation vessels, and closed-vent systems and control devices that
are used "in VHAP service."
"In VHAP service" means that the equipment contains or
contacts a fluid that is 5 percent or greater VHAPs.
RULE MILESTONES
Standards would also split the chemicals and processes to be
covered into 5 distinct groups to which the regulation would apply over
specific periods of time. The chemicals and processes to be affected
are listed in Reference Volume 1-2.1, mentioned previously, and
Reference Volume 1-3.2 which lists the chemical processes to be
covered (note that benzene and vinyl chloride are in Group I).
The rule applies to the first group 6 months after promulgation
(scheduled for Fall 1992). Thereafter, the rule would become
applicable to another group every 3 months until all of the processes
are covered. The plant owner/operator may also elect to apply the
applicability date of an earlier to a later group if he so desires.
STANDARDS FOR PUMPS AND VALVES
Pumps and Valves
The standards for pumps and valves are to be implemented in 3
phases; and standards for both pumps in light liquid service, and valves
in gas/vapor and light liquid service must have associated quality
improvement programs (QIPs). These QIPs will be discussed in detail
later. Phase I of the standards includes the provisions listed on Slide
A-6.
3-2
-------
Notes
Phase II for existing pumps and valves begins 1 year after the
applicability date of the regulation and includes a lower leak definition
than Phase I. Its provisions are listed on Slide 3-7.
Equipment base performance levels are associated with Phase
III monitoring, and encompass the provisions listed on Slide 3-8.
Phase III for Pumps and Valves
For existing units, the standards apply 2 1/2 years after the
applicability date of the regulation.
For new process units, the standards apply 1 year after start-up.
The LDAR leak definitions for pumps and valves are as follows:
• 5,000 ppm - (pumps) polymerizing monomers
• 2,000 ppm - (pumps) food/medical service
• 1,000 ppm - (pumps) all other processes (repair required
only if detection instrument reads in excess of 2,000 ppm)
The LDAR leak definition for Phase III valves is the same as
Phase II:
• 500 ppm - all valves
Phase III Pumps
The equipment base performance level is calculated on a 6
month rolling average and is defined as the larger number of the
following 2 values:
(1) 10 percent of the pumps in a process unit (or plant site), or
(2) 3 pumps in a process unit (or plant site).
If the number of pumps found to be leaking in a process unit or
plant site is equal to or greater than the larger of (1) or (2) above, the
owner/operator must implement a quality improvement program (QIP)
for pumps that complies with the requirements of § XX.X3-2 of the
HON.
3-3
-------
Notes
The formula for calculation of percent leaking pumps is
somewhat different than under the old regulation and is defined on
Slide 3-9.
QIP PROGRAMS
Generally, a QIP program consists of information gathering,
determining superior performing technologies, and replacing poorer
performance with the superior technologies until the required base
performance levels are achieved. [In this vein, the QIP is a concept
that enables plants exceeding base performance levels to eventually
achieve the desired levels without incurring penalties or being in
noncompliance].
The comprehensive QIP program for pumps is outlined in
Reference Volume 1-3.3 as follows:
The owner/operator shall comply with the QIP program until
the number of leaking pumps is less than the greater of either
10 percent of the pumps or 3 pumps, as calculated as a 6-
month-rolling average, in the process unit (or plant site). Once
this performance level is achieved, the owner/operator shall
again be under the compliance requirements of Phase III.
If in a subsequent monitoring period, the process unit or plant
site has greater than 10 percent of the pumps leaking or 3
pumps leaking, as calculated previously, the owner/operator shall
resume the QIP program.
The QIP program shall include data collection on the following
processes/equipment:
• pump type, manufacturer, seal type and manufacturer,
pump design, materials of construction; if applicable,
barrier fluid or packing material, and year installed;
• service characteristics of the emission stream such as
discharge pressure,temperature, flow rate, corrosivity, and
annual operating hours;
• maximum instrument readings;
• repair methods used and the instrument readings after the
repair.
3-4
-------
Notes
The owner/operator shall inspect all pumps that exhibit frequent
failure and recommend, as appropriate, design changes or
changes in specifications to reduce leak potential.
The data gathered shall be analyzed to determine the services,
operating or maintenance practices, and pump or pump seal
designs or technologies that have poorer than average
performance and those that are better. The analysis shall be
used to identify specific trouble areas.
The analysis shall also be used to determine if there are
superior performing pump or pump seal technologies that are
applicable to the service(s), operating conditions, or pump or
pump seal designs associated with poorer than average emission
performance.
The first analysis of the data shall be completed no later than 18
months after the start of the program, shall use a minimum of 6
months of data, may be conducted through an interior
intracompany program, and shall be done yearly for as long as
the pump is in the QIP.
There shall be a trial evaluation program for plants that have no
demonstrated superior technologies. The program shall focus on
operating and maintenance practices that have been identified
by others as having low emission performance.
The number of pump seal technologies or pumps in the trial
program shall be the lesser of 1 percent or 2 pumps for
programs involving single process units and the lesser of 1
percent or 5 pumps for groups of process units. The minimum
number of technologies in the program shall be 1.
The program shall specify and include documentation of the
designs and/or technologies to be tried, the evaluation stages,
the frequency of monitoring or inspection, the range of
operating conditions, and conclusions.
The performance trials shall be conducted for a 6-month period
beginning no later than 18 months after the beginning of the
QIP. Conclusions will be drawn no later than 24 months after
the beginning of the QIP.
Each owner/operator shall prepare and implement a pump
quality assurance program that details purchasing specifications
3-5
-------
Notes
and maintenance procedures for all pumps and pump seals in
the process unit. This program shall be implemented no later
than the start of the third year of the QIP program for plant
sites with more than 400 valves or 100 or more employees, and
no later than the start of the fourth year for other plants.
Beginning at the start of the third year of the QIP for plants
with 400 or more valves or 100 or more employees and at the
start of the fourth year for others, the owner/operator shall
replace the pumps and pump seals that are not of superior
technology. Pumps or pump seals shall be replaced at the rate
of 20 percent per year and shall continue to be replaced until all
are of superior technology.
VALVES
Valves would initially require quarterly monitoring in Phases I
and II, but the length of time between monitoring cycles could be
increased in Phase III if the percent leaking valves demonstrates
incrementally better performance over the base level. The base
performance level for valves in Phase III is defined as 2 percent
"leakers". These performance characteristics can be seen in Slide 3-11.
(1) At process units with 2 percent or greater leaking valves,
the owner/operator shall either monitor each valve once per
month; or implement a QIP program and monitor
quarterly.
(2) At process units with less than 2 percent leaking valves, the
owner/operator shall monitor each valve once each quarter.
(3) At process units with less than 1 percent leaking valves, the
owner/operator may elect to monitor each valve once every
2 quarters.
(4) At process units with less than 0.5 percent leaking valves,
the owner/operator may elect to monitor each valve once
every 4 quarters.
Calculation of leaking units is made with the same type of
equation as for pumps and can be found in § XX.X2-7 of the HON as
well as in Slide 3-12. As can be seen from this calculation, the
owner/operator can take partial credit for valves permanently removed
from the process units; and a limited number (maximum of 1 percent)
of "nonrepairable" valves (those that cannot be repaired without a
3-6
-------
Notes
process unit shutdown) may also be excluded. Additionally, plants with
fewer than 250 valves in VHAP service are subject only to LDAR and
not the base performance level of 2 percent leaking valves of Phase III.
If an owner/operator elects to use a QIP to demonstrate further
progress, he must meet the requirements of the basic QIP for valves as
has been presented in Reference Volume 1-3.4.
After the process unit has fewer than 2 percent leaking valves,
the owner/operator may elect one of three options:
(1) to continue the QIP, which exempts him from the
requirements for performance trials under the technology
review section, and further progress requirements as
outlined in the Reference Volume 1-3.4;
(2) to comply with the technology review section of the QIP
and the procedures outlined in Phase III requirements for
valves, which takes advantage of the lower monitoring
frequencies associated with lower leak rates;
(3) to discontinue the QIP (the QIP will no longer be an option
if the process unit again exceeds 2 percent leaking valves
[monthly monitoring will be required]).
CONNECTORS
The HON mandates that all connectors in gas/vapor and light
liquid service must be monitored within the first 12 months after the
rule applicability date for each process OR within 12 months of start-
up or rule promulgation, whichever is later, for new process units. It
also specifies a base performance level of 0.5 percent and a leak
definition of 500 ppm or greater.
3-7
-------
Notes
CONNECTOR MONITORING SCHEDULE
Performance Level
0.5% or greater leaks during
the last monitoring period
less than 0.5% leaks during
the last monitoring period
less than 0.5% leaks during
the last 2-year monitoring
period
Monitoring Schedule
once a calendar year
once every 2 calendar years
..OR
at least 40% during year 1 and
remainder in year 2
the
once every 4 calendar1 years
OR
at least 20% every year until all are
monitored - -
CONTINGENCY PLAN •
0.5% < leaks < 1% during
the last 4-year monitoring
period
1% or greater leaks daring
the last 4-year period
once every 2 years
.OR
at least 40% during year 1 and
remainder in year 2 .
once per calendar year
the
As can be seen in this slide, a consistent achievement of base
performance results in monitoring being required less frequently, while
failure to achieve the base performance (0.5 percent leaking
connectors) causes a source to remain in an annual monitoring cycle.
In any case, monitoring is conducted according to the schedule outlined
on
Slide 3-15a
Slide 3-15b
The percent leaking connectors is calculated using one of two
(2) equation
-------
Notes
OTHER EQUIPMENT Slide 3-18
The standards for compressors, open-ended lines, pressure relief
devices, sampling connection systems, and closed vent systems and
control devices remain essentially unchanged from existing regulations
(40 CFR 61, Subpart V.)
Agitators must meet LDAR requirements and have a leak
definition of 10,000 ppm but have no base performance levels.
Pumps, valves, connectors, and agitators in heavy liquid service;
instrumentation systems; and pressure relief devices in liquid service
are subject to instrument monitoring only if evidence of a potential
leak is found through sight, sound, or smell. (In which case monitoring
is required within 5 days of detection).
Instrumentation systems are defined as consisting of smaller
pipes and tubing that carry samples of process fluids to be analyzed to
determine process operating conditions.
ALTERNATIVE STANDARDS
Specific alternative standards have been written for batch or
cyclical processes, and total building enclosure systems. Batch/cyclical
processes are required to either; (a) meet similar standards to those for
continuous processes with the monitoring frequency prorated to time in
use or, (b) periodically pressure test the entire system, again based on
process time in use. Additionally, under (b), each batch process that
operates in VHAP service during a calendar year must be pressure
tested at least once during that same calendar year.
If the owner/operator chooses to meet monitoring standards Slide 3-19A
similar to those for continuous processes, he must base his frequency of
monitoring on the schedule presented in Slide 3-19a (with adjustments
allowed to accommodate process conditions). Exceptions to the rule
include: connectors that must be monitored the same as for continuous
processes, valves that may be monitored once each year, and agitators
that may be monitored once each quarter if the time that each valve
and/or agitator is in VHAP service is less than 2190 hours in a calendar
year. Monitoring for other equipment must be modeled after the Table
on the following slide.
3-9
-------
Notes
BATCH PROCESSES (Prorate for time of use as shown below)
BATCH PROCESS EQUIPMENT MONITORING
FREQUENCIES
Batch Process
Time in Use
0 to < 25%
25 to < 50%
50 to < 75%
75 to < 100%
Equivalent Continuous Process
Monitoring Frequency
Monthly
quarterly
quarterly
bimonthly
monthly
Quarterly
annually
semianimally
three times a year
quarterly
Semiannually
annually
annually
semiannually
Semiannually
OR
Periodically Pressure Test the System.
• When testing with a gas, Leak Definition = Pressure
Change of 1 psig/hr,
• When testing with a liquid, Leak Definition = Dripping
Liquid.
Building Enclosure Systems.
• No monitoring is required if negative pressure is maintained
in the building,
• All emissions must be routed through a control device.
Under option (b), pressure testing, using a gas; a leak is defined
as a rate of pressure change in excess of 1 psig in 1 hour,'or if there is
visible, audible, or olfactory evidence of fluid loss. For pressure tests
using a liquid, a leak is defined as dripping liquid or other evidence of
fluid loss from process units. When leaks are detected, repairs must be
made and a retest conducted before VHAP is fed to the equipment If
the process unit fails this retest or the second of 2 consecutive pressure
tests, the equipment must be repaired as soon as practicable but not
3-10
-------
later than 30 calendar days after the equipment is placed in VHAP
service.
Total building enclosure systems may forego monitoring of
pumps, valves, liquid service equipment, agitators, and connectors if the
building is kept under a negative pressure and all emissions are routed
through a closed vent system to an approved control device.
TEST METHODS AND PROCEDURES
Several changes are to be made to testing methods and
procedures as outlined in the HON, not the least of which will be the
use of EPA Method 18 for the purpose of determining the percent
VHAP in a process fluid that is contained in, or contacts equipment.
The Reference Volume 1-4, entitled EPA Reference Method 18 details
this procedure. No change has been made in the leak detection
procedures, EPA Method 21 will continue to be used here.
Calibration
There are several basic changes to instrumentation, beginning
with calibration of the instruments and indeed, with the type of
instrumentation allowable since the HON mandates that the calibration
gas must be methane. (Photoionization and infrared instruments do not
respond to methane and therefore cannot be used). Daily instrument
calibration must also be carried out according to the presentation of
Slide 3-21 - notice that calibrations are equipment and Phase specific.
INSTRUMENT CALIBRATION EQUIPMENT
Agitators
food,medical
Slide 3-20
Slide 3-21
-------
Notes
The proposed rule specifies that the detection instrument may
be calibrated at a higher methane concentration (up to 2000 ppm) than
the leak definition concentration for a specific piece of equipment for
monitoring that piece of equipment, as presented in the Slide.
However, the instrument may not be calibrated at a methane
concentration lower than that leak definition concentration for
monitoring that piece of equiptment.
The HON also addresses the problem of instrument response
factors and specifies that the one used must be determined for the
individual VHAP at 500 ppm and unless it is less than 3; it cannot be
used without adjustment. Stated differently, if any of the response
factors at 500 ppm for the VHAPs that account for 90 percent or more
by weight of the process stream are 3 or greater, then a weighted Slide 3-22a
average response factor for the VHAP in the process stream must be Slide 3-22b
calculated using the following procedure:
RF
£
1=1
AVG
£
1=1
Pressure Testing Batch Operations Slide 3-23
Lastly, procedures used to pressure test batch product-process
equipment using a gas (for example air or nitrogen) encompass testing
the equipment for 15 continuous minutes (unless a determination can
be made sooner) and using a detection device which has a precision of
±2.5 mm Hg in the test range. Procedures to be used for testing liquid
process equipment are somewhat different in that the test must
continue for 60 minutes (unless a determination can be made sooner),
and each equipment seal must be inspected for indications of fluid loss.
RECORDKEEPING/REPORTING
Recordkeeping/Reporting Slide 3-24
The HON requires that the recordkeeping system be readily
accessible and that the records should include:
ID of equipment that would be covered by the standards,
3-12
-------
Notes
ID of equipment that is found to be leaking during a monitoring
period and when it is repaired,
testing associated with batch processes,
design specifications of closed vent systems and control devices,
test results from performance tests or testing process streams for
organic content,
and information required for equipment in QIP.
Recordkeeping and reporting requirements are outlined in Reference
Volume 1-3.5. Note that the HON specifies that records must be kept
for the total number of pieces of equipment monitored.
Reporting
Under the HON owner/operators are required to submit an Slide 3-25
initial report (for existing processes within 90 calendar days of the
applicability date of the rule) that describes the source and a summary
of the equipment subject to the standards. Every 6 months, a report
must be submitted that summarizes the results of monitoring and
performance tests conducted during the period, changes in the process
unit, changes in the monitoring frequency or monitoring alternatives,
and/or initiation of a QIP (to be filed within 30 days). Reports can
be submitted on electronic media where acceptable by the
Administrator and the owner/operator. A summary of the required
items are also listed in Reference Volume 1-3.5.
3-13
-------
LECTURE 4
Notes
PORTABLE VOC ANALYZER CHARACTERISTICS
A number of portable VOC detection devices are capable of
measuring leaks from process equipment. Any analyzer can be used,
providing that it meets the specifications and performance criteria in
EPA Reference Method 21, which contains both performance
specifications and performance criteria for analyzers. In order to meet
the required performance specifications, the instrument:
• must respond to organic compounds being processed
• must be intrinsically safe for operation in explosive
atmospheres;
• must measure concentration specified in the regulation;
• must have nominal flow rate of 0.1-3 liter/min; and
• must have a scale readable to ± 5 percent of the defined
leak concentration.
The performance criteria which are specified in the Method are:
• a response time of 30 seconds or less;
• the calibration precision must be less than or equal to 10
percent of the calibration gas value;
• the instrument must be subjected to response time and
calibration precision tests prior to being placed in service;
• calibration precision must be repeated every 6 months of if
modification or replacement of the instrument detector is
required; and
• the response time must be retested after modifications to
sample pumping system or flow configuration.
There are four general classes of portable VOC analyzers:
flame ionization detectors, photoionization detectors, catalytic
combustion analyzers, and infrared analyzers. However, there are a
Notes
Slide 4-1
Method 21
Slide 4-2
Slide 4-3
4-1
-------
Notes
wide variety of instrument designs within each class. This section will
only consider the first three types since at the present time, infrared
analyzers are not used frequently for fugitive VOC leak detection.
Inspectors should fully understand operating principles and
design characteristics of the instruments. This is so they can
understand the importance of check-out procedures, calibration
procedures, and field monitoring procedures.
Lectures 5, 6
FLAME IONIZATION DETECTORS
In a flame ionization detector (FID), the sample is introduced
into a detection chamber where it is exposed to a hydrogen flame. The
flame is surrounded by negative collecting electrodes. When most
organic vapors burn, they form positively-charged carbon ions as
intermediate products of combustion. The ion current between the
flame and the collector is measured electronically. Pure hydrogen
burning in air produces very little ionization, so background effects are
minimal The calibrated output current is read on a panel meter or
chart recorder.
In FIDs used in portable instruments the oxygen used for
organic vapor combustion is drawn from the sample gas itself.
Therefore, there are two separate gas streams approaching the burner
chamber: the sample gas and the hydrogen stream. This "two stream"
design is different than laboratory scale FIDs in which a separate
combustion air stream is supplied to the burner. The response of the
portable ("two stream") instruments is different than the response of
the larger, heavier laboratory ("three stream") units.
Carbon monoxide and carbon dioxide do not produce inter-
ferences. However, if water condenses in the sample tube, it may
block the tube and give erratic readings. As with most gas samplers, a
filter is used to remove any particulate matter which may be present.
Certain organic compounds that contain nitrogen, oxygen, or
halogen atoms give a reduced response. In addition, some organics
may not give any response at all. Also, FIDs manufactured by different
companies may respond differently to the same chemical compound.
Reference Method 21 requires that a response factor be determined
for each compound that is to be measured. These response factors are
discussed later. Presently, FIDs are one of the most accepted and
widely used detectors for measuring organic leaks from process
equipment.
Slide 4-4
Slide 4-5
Slide 4-6
4-2
-------
Notes
Changes in the sample gas flow rate have almost a linear effect Slide 4-7
on the instrument measurement, since FIDs detect the total quantity of
positive ions being generated in the burner. However, at very high or
very low sample gas flowrates, the air-to-fuel ratios of the hydrogen
flame can be misbalanced stoichiometrically that combustion can not be
sustained. FIDs are also sensitive to air infiltration prior to the burner.
Since the organic vapor is at least partially oxidized in the
hydrogen flame, it is impossible to collect the effluent from the
instrument for further analysis. For this reason, FIDs are classified as
"destructive" instruments.
PHOTOIONIZATION DETECTORS
Photoionization detectors (PID) utilize high energy ultraviolet Slide 4-8
light (instead of a flame) for ionization of organic vapors. The lamps Slide 4-9
are mounted on one side of the exposure chamber and have a high Slide 4-10
quality quartz lamp window for transmission of the UV light.
In the photoionization process, ultraviolet light ionizes a
molecule as follows: R & hv -» R+ + e", where R+ is the ionized
species and hv represents a photon with energy greater than or equal
to the ionization potential of the molecule. Generally all species with
an ionization potential less than the ionization energy of the lamp are
detected. Because the ionization potentials of all major components of
air (O2, N2, CO, CO2, and-H2O) is greater than the ionization energy
of the lamps in general use, they are not detected.
The sensor consists of an ultraviolet (UV) light source that emits
photons. A chamber adjacent to the sensor contains a pair of
electrodes. When a positive potential is applied to one electrode, the
field that is created drives any ions formed by the absorption of UV
light to the collector electrode, where the current (proportional to the
concentration) is measured.
Only a very small fraction of the organic vapor is ionized in Slide 4-11
photoionization analyzers, due partially to the short light path length
and due partially to the short residence time in the exposure chamber.
Accordingly, the response of these instruments are essentially
insensitive to sample gas flowrate. The PID instruments are similar to
the FID instruments in that they are sensitive to air infiltration prior to
the burner.
4-3
-------
Notes
Furthermore, the sample gas exhausted from the same
instruments can be collected and saved for further analyses such as gas
chromatograph tests. For this reason, PID instruments are classified as
"nondestructive."
The UV lamp optical windows for photoionization analyzers
must be cleaned whenever contaminants have condensed on the
surface or whenever liquids have been captured along with the sample
gas stream, the windows are cleaned "in-place" without removal from
the instruments. A small quantity of manufacturing supplied cleaning
compound is used for cleaning. The need for cleaning is indicated by a
sudden change in the instrument response or an observed change in
the calibration data.
CATALYTIC COMBUSTION ANALYZERS
Combustion analyzers utilize either the thermal conductivity of a
gas, or heat produced by combusting the gas. By far, the most
common method used in portable VOC detection devices is measuring
the heat of combustion. These devices are referred to as catalytic
combustion analyzers.
The catalytic combustion analyzer oxidizes the organic vapor in Slide 4-12
a sintered metal reaction chamber equipped with two wires. One is Slide 4-13
catalyst coated to promote oxidation and the other wire of similar
length is not coated. The heat of combustion around the coated wire
changes its electrical resistance relative to the uncoated wire. The
difference in resistance between the coated wire and the reference wire
(whose resistance is unaltered by the oxidation of combustible gas) is
sensed by a Wheatstone Bridge circuit and a current signal is
generated. This signal is then measured and related to VOC
concentration.
The basic operating characteristics of the catalytic combustion Slide 4-14
analyzer are identical to those of the flame ionization instruments. The
instrument is sensitive to sample gas flow rate since changes in the
quantity of organic vapor affect the heat of combustion released near
the sensing wire. The catalytic combustion instruments are classified as
"destructive" since most of the organic vapor is at least partially
oxidized while passing through the unit, and they are sensitive to air
infiltration prior to the detector cell.
4-4
-------
Notes
RESPONSE OF INSTRUMENTS
One important criterion in the selection of organic vapor
detectors is the response of the instrument to the specific chemical or
chemicals present in the as stream. The abilities of the major classes
of organic vapor analyzers to detect different organic chemicals differ
substantially.
Inspectors should develop a clear understanding on the uses and
limitations of response factor data. The response factor, defined
below, provides a convenient index of this property.
Reference 1
Response Factor =
Actual Concentration
Instrument Indicated Concentration
Slide 4-15
A response factor of 1.0 means that the instrument readout is
identical to the actual concentration of the chemical in the gas sample.
As the response factor increases, the instrument readout is
proportionally less than the actual concentration. It should be
understood that a high response factor means that a given instrument
does not detect a compound very well. The following examples may
help explain the definition.
Example 1.
Actual Concentration
Instrument Gauge Reading
Response Factor
Example 2.
Actual Concentration
Instrument Gauge Reading
Response Factor
Example 3.
Actual Concentration
Instrument Gauge Reading
Response Factor
Slide 4-16
10,000 ppm
5,000 ppm
2
1,000 ppm
3,000 ppm
0.33
= 100,000 ppm
= 10,000 ppm
= 10
Slide 4-17
Slide 4-18
If the regulatory limit is 10,000 ppmv (observed), the use of an
instrument with a response factor of 10 for the specific chemical(s)
would allow an actual concentration of 100,000 ppmv. Conversely, the
Slide 4-19
4-5
-------
Notes
use of an instrument with a response factor of 0.1 would indicate that
the regulatory limit of 10,000 ppmv had been exceeded when the actual
concentration is only 1000 ppmv. Typical response factors vary over a
range of 0.1 to 40. The lower the response factor, the more sensitive a
given instrument is for a specific type or organic compound.
In accordance with Method 21, only instruments having response
factors less than 10 for the organic compounds being monitored may be
used for leak detection. The response factor must be determined
either by consulting published tabular data provided by instrument
manufacturers or the U.S. EPA, or alternatively by laboratory testing of
the specific instrument being used with the chemicals of interest.
Obviously, the latter approach is more accurate. However, it is very
expensive for instruments used for a large number of compounds.
Response factor tables are provided in the Portable VOC Analyzer
User's Manual.
Response factors for many compounds are very sensitive to the
actual concentration of the organic vapor. This is illustrated by a series
of examples drawn from EPA sponsored studies performed during the
development of Method 21.
Example 1: Response Factor Data for OVA-108 FID, Xylenes
Slide 4-20
Reference 2
Slide 4-21
Slide 4-22
Compound Actual Concentration
(ppm)
para-Xylene
meta-Xylene
ortho-Xylene
50
500
7700
200
1500
3000
200
1500
3000
Instrument Response
Factor
3.49
3.70
2.27
1.04
0.60
0.42
0.89
0.86
0.39
4-6
-------
Notes
Example 2: Response Data for OVA-108 FID, Paraffinic Compounds Slides 4-23 and
4-24
Compound Actual Concentration Instrument Response
(ppm) Factor
Ethane 1000 1.04
3000 1.16
4500 0.57
Propane 1000 0.84
2000 3.12
4000 0.59
Pentane 200 1.33
1500 0.94
5000 0.48
n-Hexane 150 0.48
550 0.57
1500 0.57
3200 0.63
8000 0.69
Heptane 200 1.00
1500 0.67
4000 0.32
Decane 200 10.77
300 0.83
400 1.61
4-7
-------
Notes
Example 3: Response Factor Data for OVA-108 FID, Aromatic Slide 4-25
Compounds
Compound Actual Concentration Instrument Response
(ppm) Factor
Benzene 50 0.88
2000 0.32
2800 0.28
5000 0.51
Toluene 200 0.67
1500 0.49
3000 0.39
Ethylbenzene 50 0.52
1500 0.83
8000 1.23
Example 4: Response Factor Data for OVA-108 FID, Chlorotoluenes Slide 4-26
Compound Actual Concentration Instrument Response
(ppm) Factor
Meta-chlorotoluene 200 0.61
1500 0.53
3100 0.50
Ortho-chlorotoluene 200 0.85
1500 0.63
3100 0.63
Para-chlorotoluene 200 0.75
1500 0.55
3200 0.51
It should be also noted that most response factors have been
determined at concentrations less than 10,000 ppm and that
extrapolations have been performed to calculate the response factors at
the action level of 10,000 ppm. It should also be noted that the
concentration variability of response factor generally does not affect
conformance with the Method 21 response factor upper limit of 10.
4-8
-------
Notes
Laboratory studies conducted under carefully controlled Slide 4-27
conditions have demonstrated some instrument-to-instrument variations
in response to known concentration reference standards. The extent of
these differences are illustrated in the following examples.
The following three examples are admittedly extreme examples
of instrument-to-instrument variation. This could be due to subtle
design differences, sample capture differences, or even undetected
instrument malfunctions during the studies. Nevertheless, this type of
data underscores the importance of not using published response factor
to calculate actual concentration. It also suggests the value of
performing independent laboratory analyses to determine instrument
specific response factors.
Example 1: Instrument-to-instrument Variations for OVA-108 FID: Slide 4-28
Cyclohexanol
Compound Actual Concentration Response Factors at
(ppm} 10.000 ppm
Instrument 1 Instrument 2
Cyclohexanol 200 1.98 2.21
700 1.67 1.71
1200 1.21 1.41
Example 2: Instrument-to-instrument Variations for Catalytic Slide 4-29
Combustion Analyzer: Xylenes
Compound Actual Concentration Response Factors at
(ppm} 10.000 ppm
Instrument 1 Instrument 2
para-Xylene 50 150 1.51
500 9.43 3.98
7700 7.83 4.00
meta-Xylene 200 3.53 1.70
1500 9.44 2.01
3000 12.84 1.64
4500 15.01 1.53
7000 37.86 1.73
4-9
-------
Notes
Example 3: Instrument-to-Instrument Variations for Catalytic Slide 4-30
Combustion Analyzer: Ethylbenzene
Compound Actual Concentration Response Factors at
fppm) . 10.000 ppm
Instrument Instrument Instrument
1 2 3
Ethylbenzene 50 1.93 1.16 N.D.
500 10.50 2.62 N.D.
4000 32.62 4.11 1.32
8000 27.09 3.05 1.14
The response factor variability problems discussed during the Slide 4-31
last several examples do not necessarily limit the usefulness of portable
VOC analyzers or preclude uses of tabular response factor data. The
problems have been discussed only for the purpose of encouraging
caution in the use of the response factor data. Response factors should
be used to select appropriate instruments for specific applications, but
not used to calculate actual concentration.
To a certain extent, the instrument operators must learn to
ignore the concentration scale on the instruments. In fact, the primary
use of "readings" below the VOC action levels will be to provide
qualitative indications of potential inhalation hazards.
The portable VOC analyzers when calibrated with a reference
gas different than the emission compound(s) can be used simply as a
classifier. It tells the inspector if a given component in VOC service
has fugitive emissions either above or below the regulatory action level
(generally 10,000 ppm).
4-10
-------
REFERENCES AND ADDITIONAL READING MATERIAL
1. Joseph, G., and M. Peterson, "APTI Course SI:417, Controlling VOC Emissions from
Leaking Process Equipment, Student Guidebook," EPA-450/2-32-015, August 1982.
2. U.S. Environmental Protection Agency, "Portable Instruments User's Manual for
Monitoring VOC Sources," EPA-340/1-86-015, June 1986.
3. Engineering Science, "Benzene Equipment Leak Inspection Manual," EPA-340/1 -90-001,
July 1990.
4. DuBose, D-A. and G.E. Harris, "Response Factors of VOC Analyzers at a Meter Reading
of 10,000 ppmv for Selected Organic Chemicals, EPA-600/2-81-051, March 1981.
5. PEDCo Environmental, "Summary of Available Portable VOC Detection Instruments,"
Report Prepared for USEPA Contract 68-01-2147, June 1980.
6. Brown, G.E., et. ah, "Response Factors of VOC Analyzers Calibrated with Methane for
Seclected Organic Chemicals," Report Prepared for USEPA Contract 68-02-3171, Task 001,
September 1980.
7. Brown, G.E., et ah, "Response Facotrs of VOC Analyzers Calibrated with Methane for
Selected Organic Chemicals, Project Summary," EPA-600/S2-81-002, May 1980.
8. Brown, G.E., et al., "Project Summary Response Factors of VOC Analyzers Calibrated with
Methane for Selected Organic Chemicals," EPA-600/S2-81-002, May 1981.
9. DuBose, D.A. and G.E. Harris, "Project Summary Response Factors of VOC Analyzers at
a Meter Reading of 10,000 ppmv for Selected Organic Compounds," EPA-600/S2-051,
September 1981.
10. DuBose, D.A. et al., "Project Summary, Response of Portable VOC Analyzers to Chemical
Mixtures," EPA-600/S2-81-110, September 1981.
11. Menzies, K.T. and R.E. Fasano, "Evaluation of Potential VOC Screening Instruments,"
EPA-600/7-82-063, November 1982.
12. Flanagan, G., "Selecting A Volatile Organic Chemical Detector," Chemical Engineering
Progress, September 1984, pp 37-44.
4-11
-------
LECTURE 5
PORTABLE VOC ANALYZER CHECKOUT
AND CALIBRATION
Notes
This section concerns portable VOC instrument checkout and
calibration procedures. It will also discuss the support facilities
necessary for a portable VOC analyzer program. The calibration
procedures are taken directly from Method 21. The checkout
procedures, however, are an addition and highly recommended to
insure that the instrument taken to the site is in good mechanical and
electrical operating condition.
CHECKOUT PROCEDURES
The checkout procedures discussed in this section are not Slide 5-1
specific requirements of Method 21. However, the time used for Slide 5-2
checkout procedures is well spent since there is no need to attempt
field work if the instrument is either not working properly or if it will
fail soon after beginning. This section will discuss checkout procedures
for the three types of analyzers discussed in Lecture 4. Lecture 4
Flame lonization Detectors (FIDs)
The first pre-check is to confirm that there is sufficient hydrogen
to fuel the instrument burner. If necessary, the instrument's hydrogen
tank should be filled.
The next step in the inspection procedure is to confirm that the
battery is adequately charged. Battery failure has been one of the most
commonly reported problems and is due primarily to improper
charging practices. Some FIDs have lead acid batteries which should
be left on the charger whenever the instrument is not in use. Other
portable VOC analyzers have nickel cadmium batteries which should
be charged for 10-12 hours (refer to manufacturer's recommendations).
Failure to adequately charge either type of battery could lead to a
discharge problem which in turn could necessitate installation of a new
battery. In all cases, it is advisable to take a spare, fully charged
battery to the inspection site.
Slide 5-3
5-1
-------
Notes
It is necessary to allow at least a 10-minute warmup period
before checking the amplifier electronic linearity. This is an important
check since portable VOC analyzers for fugitive VOC detection are
used in two quite different concentration ranges. The action level
concentrations for leaks from most components in VOC service is
10,000 ppm. However, some units are subject to a no detectable
concentration limit which is equivalent to 500 ppm above background.
The next step is a leak check of the sample gas handling system.
These checks are made by briefly blocking the sample gas line at
various locations and listening for the characteristic "starved pump"
sound. If the appropriate pump sound is not heard, then an air leak
must be found and eliminated. It is appropriate to start with the
sample gas line fitting leading into the instrument case.
Before attaching the probe to the readout assembly, it should be
checked for any deposition of material on the paniculate filter installed
within the instrument. This should be replaced if there is any visible
signs of contamination. A check should also be done for any organic
deposits or moisture on the surfaces of the probe. If necessary, the
probes should be cleaned to remove any deposits. After completing
the check for cleanliness, the probe should be reassembled and
attached to the readout gauge so the probe leak checks can be
completed.
The final pre-check of an FID is to measure the sample gas flow
rate. The most common method of checking this is by attaching a
calibrated rotameter to the probe. However, for low flow rates a soap
bubble flowmeter may be more appropriate. The indicated flow rate
should be recorded in a bound notebook which has the instrument's
operation and maintenance data. This information is important since
the VOC concentration response is directly proportional to sample gas
flow rate. Changes are possible due to pump problems or gas flow
blockages within the instrument. If there has been a significant change
from the baseline levels it may be necessary to either replace the pump
or clean the flame arresters. It is also important to complete a brief
leak check to confirm that the readings are not biased low due to air
infiltration at the top of the rotameter.
In FIDs, there is a flame arrestor usually mounted between the
mixer/burner and the outside of the instrument case. Occasionally this
flame arrestor is removed for cleaning. If it is not replaced, the
instrument could be operated with a hydrogen flame exposed to the
outside air. Obviously, it is critical to prevent this potentially explosive
5-2
-------
Notes
condition and the presence of the flame arrester is checked before
each use.
Photoionization Detectors (PIDs)
The pre-check procedures for photoionization analyzers are only Slide 5-4
slightly different from those which have already been discussed. Just
like in the earlier examples, one of the first steps is to confirm that the
battery is adequately charged.
One of the unique pre-checks of photoionization units is to
inspect the optical surface of the lamp to determine if there are any
deposits. These can absorb the UV light and reduce the capability of
the system to detect VOC material. Even a minute coating of material
is sufficient to affect the instrument performance. If any of this
material is apparent the instrument should be carefully cleaned in
accordance with the manufacturer's recommendations. Checks should
also be made for probe condition, detector response and the sample
gas flow rate.
Catalytic Combustor Analyzers
The pre-checks for the catalytic conducting instruments closely Slide 5-5
parallel those previously discussed for FIDs. The scope of the pre-
checks include the battery status check, probe and pre-filter cleanliness
check, leak check of the probe, detector response check, and a
measurement of the sample gas flow rate.
CALIBRATION PROCEDURES
Instruments used to determine compliance of industrial facilities Slide 5-6
must be accurately calibrated on a daily basis. The calibration
precision test, response time, and response factor tests also should be
performed to confirm that the instruments are operating properly for
the specific application(s).
Calibration requirements for VOC instrumentation are specified Slide 5-7
in EPA Method 21. The requirements pertaining to calibration are Method 21
briefly summarized here, and the complete Method 21 regulations,
Reference Volume 1-5.
• The instruments should be calibrated daily.
5-3
-------
Notes
• The gas concentration used for calibration should be close to
the leak definition concentration.
• The calibrant gas should be either methane or hexane.
• A calibration precision test should be conducted every
month.
• If gas blending is used to prepare gas standards, it should
provide a known concentration with an accuracy of ± 2
percent.
The daily calibration requirement specified in Method 21 gives
individual instrument operators some flexibility. The calibration could
consist of a multipoint calibration in the lab, or it could be a single-
point "span check" at the facility.
Method 21 does not specify where the calibration must take Slide 5-8
place. Obviously it would be simpler to conduct the calibration test in
the agency laboratory rather than after arrival at the plant.
Although the span checks mentioned above would in most cases
qualify as the required daily calibrations; a separate calibration test for
organic vapor analyzers should be conducted whenever possible.
Calibrations performed in the regulatory agency laboratory as
compared to calibrations done in the field are conducted under more
controlled conditions because uniform day-to-day calibration gas
temperatures and calibration gas flow rates can be maintained in the
laboratory. Furthermore, the initial calibration test provides an
excellent opportunity to confirm that the entire instrument system is
working properly before it is taken into the field. The laboratory
calibration data should be carefully recorded in an instrument
calibration/maintenance notebook, and this calibration should be
considered as the official calibration required by the regulations.
The laboratory calibration is best performed by the personnel
assigned primary responsibility for the maintenance and testing of all
the agency organic vapor analyzers. This ensures the use of proper
and consistent procedures. If instrument problems are identified, the
instrument can either be repaired or the field inspector can be issued
another unit that is operating properly.
The instruments used in accordance with Method 21 must be
calibrated by using either methane or hexane at concentrations that are
close to the leak-detection limits. In most cases, the leak-detection
5-4
-------
Notes
limit is 10,000 ppmv, however, for certain sources, it is 500 ppmv above
the background levels.
Methane-in-air is generally the preferred calibrant gas for the
high concentration range. A hexane-in-air concentration of 10,000
ppmv should not be prepared because it is too close to the lower
explosive limit. Also, some hexane can condense on the calibration bag
surfaces at this high concentration. If hexane-in-air calibrations are
necessary, the chosen concentration should be a compromise between
the need for adequate calibration of leak-detection levels and the
practical safety and reproducibility problems inherent in the use of
hexane. Some VOC instruments, such as photoionization and instru-
ments, do not respond to methane. With these units, a different
calibration gas should be used.
The following are some of the various ways to calibrate the
portable instrument on site:
• Use certified gas cylinders provided by the source being
inspected.
• Use disposable gas cylinders with the appropriate gas
composition and concentration.
• Use a gas sampling cylinder with a gas blending system.
Transporting large pressurized gas cylinders has not been listed
since most agencies do not have the vehicles necessary for this purpose.
It is not safe to transport unsecured, pressurized gas cylinders in
personal or State-owned cars. Furthermore, there are specific
Department of Transportation (DOT) regulations governing the
shipping of compressed gases.
Using the source's gas cylinders is certainly the least expensive
approach for a regulatory agency; however, the appropriate gas
cylinders are not always available. Also, the use of the source's
cylinders prevents the agency from making a completely independent
assessment of the VOC fugitive leaks and from evaluating the adequacy
of the plant's leak-detection program.
Using disposable cylinders of certified calibration gas mixtures is
relatively simple because no on-site blending is necessary and the
cylinders are easily transported. The calibration gas mixture may be
fed to the instrument directly by using a preset regulator that provides
5-5
-------
Notes
constant gas flow and pressure; or the gas can be fed into a Tedlar* or
Teflon* bag, from which it is drawn into the portable instrument.
The response time of an analyzer is defined as the time interval Slide 5-9
from a step change in VOC concentration at the input of a sampling
system to the time at which 90 percent of the corresponding final value
is reached as displayed on the analyzer readout meter. This time must
be less than or equal to 30 seconds and must be determined for the
analyzer configuration that will be used during testing. The response
time test is required before placing an analyzer in service. If a
modification to the sample pumping system or flow configuration is
made that would change the response time, a new test is required
before further use.
The response time of an analyzer is determined by first
introducing zero gas into the sample probe. When the meter has
stabilized, the system is quickly switched to the specified calibration
gas. The time, from the switching to when 90 percent of the final
stable reading is reached, is noted and recorded. This test sequence
must be performed three times. The reported response time is the
average of the three test.
Calibration precision is the degree of agreement between Slide 5-10
measurements of the same known value. To ensure that the readings
obtained are repeatable, a calibration precision test must be completed
before placing the analyzer in service, and at 3-month intervals, r at the
next use, whichever is later. The calibration precision must be equal to
or less than 10 percent of the calibration gas value.
To perform the calibration precision test, a total of three test
runs are required. Measurements are made by first introducing zero
gas and adjusting the analyzer. The specified calibration gas
(reference) is then introduced and the meter reading is recorded. The
average algebraic difference between the meter readings and the
known value of the calibration gas is then computed. This average
difference is then divided by the known calibration value and multiplied
by 100 to express the resulting calibration precision as percent.
SUPPORT FACILITIES NECESSARY FOR PORTABLE VOC ANALYZERS
There are certain laboratory and shop facilities which are Slide 5-11
necessary to operate and maintain VOC analyzers. There are a Slide 5-12
number of possible hazards involved in the maintenance, testing, and
calibration of these analyzers. Therefore, it is recommended that an
5-6
-------
Notes
inspector not try to operate, maintain, and calibrate these instruments
in an office environment. In a poorly ventilated office space or
building, the emissions of small quantities of potentially toxic or
carcinogenic gases could create an inhalation risk. There is also the
potential for a major accident due to the careless handling of the a
high-pressure hydrogen cylinder or calibration gas cylinder in the
crowded office space. A laboratory facility is needed that has proper
ventilation hoods, secure cylinder mounts, bench space, and storage
space.
A properly designed laboratory hood is important for calibrating Slide 5-13
and checking portable VOC analyzers. This should be large enough to
accommodate the portable instrument and also the calibration gas
sources. The hood should be free of any contaminants on the working
surfaces and should not be used for chemical storage. The hood
ventilation fan should be used to remove any exposure to calibration
gases or gaseous emissions from the instruments. It is important to
minimize exposure to the calibration gases since these are generally at
relatively high concentrations. Also, some of the calibration gases in
common use such as benzene and 1,3-butadiene, are suspected
carcinogens.
Secure cylinder brackets are needed for all hydrogen tanks and
other gas cylinders. If these cylinders were knocked over the main
valve could be broken off and the cylinder would become a dangerous
projectile.
A moderate amount of bench space is needed simply for routine Slide 5-14
instrument maintenance and checks. The following are common
examples of this:
• Sample gas flow rates must be determined daily using soap
bubble flow meters and rotameters.
• Photoionization detectors must be disassembled and cleaned
regularly.
• Catalytic combustion analyzers must be removed from
instrument cases for adjustment of zero scales.
• All types of units must be partially disassembled when
excessive quantities of vapor and/or droplets have entered
the unit.
5-7
-------
Notes
There should also be adequate storage space with the Slide 5-15
necessary spare parts and supplies for repairing the instrument. The
laboratory or shop area is also a good place to keep the instrument's
maintenance and calibration log book since data and notes must be
entered on a fairly routine basis.
In summary, some basic laboratory or shop facilities are
necessary to operate and maintain portable VOC analyzers. For safety
reasons, attempting to calibrate and check out unit in a typical
professional office setting is not prudent. If an inspector does not have
access to laboratory facilities, it is recommended inspections be
restricted to the level 2 type inspection in which source personnel are
observed conducting the routine screening tests.
5-8
-------
REFERENCES AND ADDITIONAL READING MATERIAL
1. Joseph, G., and M. Peterson, "APTI Course SI:417, Controlling VOC Emissions from
Leaking Process Equipment, Student Guidebook," EPA-450/2-82-015, August 1982.
2. U.S. Environmental Protection Agency, "Portable Instruments User's Manual for
Monitoring VOC Sources," EPA-340/1-86-015, June 1986.
3. Engineering Science, "Benzene Equipment Leak Manual," EPA-340/1-40-001, July, 1990.
4. Becker, J.H., et al., "Instrument Calibration with Toxic and Hazardous Materials,"
Industrial Hygiene News, July 1983.
5-9
-------
LECTURE 6
LEAK MONITORING PROCEDURES, PROBLEMS,
AND ERRORS
General monitoring techniques as well as specific procedures for
different equipment types are described in Method 21. However, there
are several potential problems which should be discussed to help
prevent errors in monitoring. An inspector should be able to identify,
avoid, and correct common screening mistakes. This knowledge is
helpful regardless if he or she is personally conducting the monitoring
or observing plant personnel. This lecture presents the general
screening procedures contained in Method 21 and also discusses
problems associated with the use of portable VOC analyzers for this
monitoring.
Notes
MONITORING PROCEDURES
Method 21 prescribes a general methodology for monitoring for
equipment leaks which is applicable to all types of portable VOC
analyzers. The probe inlet should be placed close to the surface of the
component interface where leakage could occur. The probe should
then be moved around the interface periphery while observing the
instrument readout. If an increased meter reading is observed, the
interface should be slowly sampled using various probe orientations. If
the gauge spikes above 10,000 ppm, the component being checked
should be classified as leaking. If the instrument probe can be held at
the location of the maximum gauge reading for two times the
instruments response time without exceeding 10,000 ppm, the
component should be classified as nonleaking.
As examined in Lecture 2, each equipment type has certain
areas which are more prone to develop leaks. Therefore, when
screening for equipment leaks it is important to consider the
characteristics of the component so that a leak will not be overlooked.
Following are examples of the application of the general technique
given above to specific types of equipment.
Valves - The most common source of leaks from valves is at the
seal between the stem and housing. The probe should be placed at the
interface where the stem leaves the packing gland. The stem
circumference should be sampled. Also, the probe should be placed at
the interface of the packing-gland-take-up-flange seat and the
6-1
Slide 6-1
Method 21
Lecture 2
Slides 6-2 thru 6-7
-------
Notes
peripheries sampled. In addition, valve housings of multipart
assemblies should be surveyed at the surface of all interfaces where
leaks could occur.
Pumps and compressors - A traverse at the outer surface of the
pump or compressor shaft and seal interface should be conducted. If
the source is a rotating shaft, the probe inlet should be positioned
within 1 cm of the shaft seal interface. A tygon probe extension should
be attached to prevent a metal-to-metal contact with the rotating shaft.
If the housing configuration prevents a complete traverse of the shaft
periphery, all accessible portions should be sampled. All other joints
on the pump or compressor housing where leaks could occur should
also be sampled.
Pressure relief devices - The configuration of most pressure
relief devices prevents sampling at the sealing seat interface. For those
devices equipped with an enclosed extension, or horn, the probe inlet
should be placed at approximately the center of the exhaust area to the
atmosphere.
Process drains - For open drains, the probe inlet should be
placed at approximately the center of the area open to the atmosphere.
For covered drains, the probe should be placed at the surface of the
cover interface and a peripheral traverse conducted.
Open-ended lines or valves - The probe inlet should be placed
at approximately the center of the opening to the atmosphere.
Seal system degassing vents and accumulator vents - The probe
inlet should be placed at approximately the center of the opening to
the atmosphere.
Flanges and other connections - For welded flanges, the probe
should be placed at the outer edge of the flange-gasket interface and
the circumference of the flange sampled. Other types of
nonpennanent joints (such as threaded connections) should also be
sampled with a similar traverse.
A slightly different procedure should be used for equipment
designated as "no detectable emissions". The operator should
determine the background concentration around the source by moving
the probe inlet randomly upwind and downwind at a distance of 1 to 2
meters from the source. If an interference exists with this
determination due to a nearby emission or leak, the local ambient
concentration may be determined at distances closer to the source, but
Slides 6-8 thru 6-10
Slides 6-11, 6-12
6-2
-------
Notes
the distance should not be less than 25 centimeters. The probe inlet
should then be moved to the surface of the source and the same survey
described in the preceding section conducted. If an increase greater
than 5% of the leak definition concentration is obtained, the results
should be recorded and reported as specified by the regulation.
For those cases where the regulation requires installing a
specific device, or ducting or piping specified vents to a control device,
the existence of these conditions should be visually confirmed. When
the regulation also requires that "no detectable emissions" exist, visual
observations and sampling surveys are required. Examples of this
technique are as follows:
Pump or compressor seals - If applicable, the type of shaft seal
should be determined. A survey of the local area ambient VOC
concentration should be performed and a determination made if
detectable emissions exist as described above.
Seal system degassing vents, accumulator vessel vents, pressure
relief devices - If applicable, the inspector should observe whether or
not the proper ducting or piping exists. Also, her or she should
determine if any sources exist in the ducting or piping where emissions
could occur in front of the control device. If the required ducting or
piping exists, and there are no sources where the emissions could be
vented to the atmosphere in front of the control device, then it is
presumed that "no detectable emissions" are present.
PROBLEMS AND ERRORS IN EQUIPMENT LEAK MONITORING
One of the main problems in monitoring is locating a leaking Slide 6-13
source. As noted above, the normal procedure is to traverse the
potential leak location with the probe within 1 centimeter. The close
location is necessary because of the relatively poor capture
effectiveness inherent with the probe. The probe is limited to negative
pressure type sample gas capture. This has a very limited distance of
effectiveness, and the capture effectiveness decreases very rapidly with
distance from the probe. Several diameters away from the probe
(maybe even less than a half inch), there can be almost negligible
capture. The presence of a strong cross-draft due to ambient wind
further reduces the probe capture capability. Therefore, it is very easy
to miss a leak unless care is taken to place the probe very close to the
component being screened as specified in the method.
6-3
-------
Notes
It is equally important that the probe be oriented properly. A Slide 6-14
leak usually leaves the component under positive pressure and persists
as a narrow jet a long distance with only limited dispersion and only
gradual deceleration. Therefore, the instrument operator must orient
the probe so that the positive pressure characteristics of the leak
benefit the capture. That is, the probe should be held parallel to the
flow in the center of the leaking gas stream. This means that the
operator must not only hold the probe very near the component, but
must attempt various orientations to assure that a leak is not missed.
This poor capture capability which is inherent in all types of Slide 645
analyzers makes them especially sensitive to changes in sample gas flow
rates. As the flow rate decreases, the ability to draw in the emission
plume decreases. This increases the importance of keeping the probe
in close proximity to the component and trying various orientations.
The regulations define a leak as 10,000 ppm or above. A leak Slide 6-16
can range from 10,000 ppm to extremely high concentrations of over
1,000,000 ppm. The high pressure conditions present in many instances
will produce a high velocity plume with substantial mass emission rates.
Other process conditions are notable, particularly temperature. High
temperatures present in the process stream make for very hot leaking
gas streams. This not only presents safety concerns, but problems
associated with certain compounds which will condense at ambient
temperatures.
There are several types of problems that prolonged exposure to
high VOC concentration can cause. In a flame ionization detector, if Slide 6-17
hydrocarbon concentrations reach above about 70,000 to 120,000 ppmv,
there may not be sufficient oxygen in the sample gas to support
combustion in the burner. Therefore, flame-out can occur. Any
further screening tests would not indicate any leaks because the unit
would not be operating properly. Most instruments have a flame-out
alarm, but this may not be heard in the noisy environments of most
plants.
High concentrations of hydrocarbons can also lead to very high Slide 6-18
detector temperatures and the loss of catalyst in catalytic combustion Slide 6-19
units. Condensation of nonvolatile vapors on photoionization unit lamp
windows can reduce the sensitivity of the instrument
The condensation of material in the probe and sampling lines
can be a problem for all types of instruments. For these reasons, the
analyzer operator should monitor the hydrocarbon concentration whfle
slowly approaching the valve stem, pump shaft seal, or other source. If
6-4
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Notes
the instrument gauge indicates high concentrations, the specific leak
site on the valve stem or pump seal should be approached very
carefully. Furthermore, there is little to be gained by maintaining the
probe at the leak site for two times the response time if the instrument
already indicates a concentration above the leak. To the extent
possible, VOC analyzers should be protected against high organic vapor
concentrations.
In summary, it is important to be close and properly oriented, Slide 6-20
but only for a brief time in the case of a leak. As soon as a leak is
indicated, the instrument should be withdrawn. Proper procedures
should be to come in toward the leak, get close, move around in
different orientations to try to find a plume, and once a positive
indication is shown that a leak exists, the probe should be moved away
to protect the instrument.
It is also important to remain aware of any liquid spray from Slide 6-21
equipment, especially pumps, which could result in contamination of
probe and sample lines. While approaching a component it is
important to visually check for any liquid spray. If some is obvious, an
attempt should not be made to use the instrument. Even if no spray is
apparent, it is good practice to attach a small section of plastic tubing
with some fiberglass to the probe as a prefilter. A fiberglass wool
prefilter also will help to protect against droplet intake.
It is equally important to consider the instrument problems Slide 6-22
which can be created by adverse weather conditions. Portable VOC
analyzers should not be used when it is raining. Droplets inadvertently
drawn into the probe can cause minor damage to the various types of
sensors. For example, in flame ionization units the water can partially
clog the flame arresters. Droplets can also coat the optical surfaces of
the photoionization detector.
While conducting fugitive VOC screening tests it is important to Slide 6-23
understand and adhere to all agency and plant safety procedures.
Valves in high locations should be avoided unless there is safe and
convenient access for the person using the instrument. Standing on a
portable ladder while using the instrument is difficult since the 5 to 15
pound instruments can create a balance problem and both hands must
be free to hold onto the ladder. For similar reasons, valves that can
only be reached by standing on a fixed caged ladder and reaching
through the cage should be avoided.
It is obviously important to avoid hot surfaces and working
equipment while walking around the facility. And also, only those
6-5
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Notes
portable analyzers and recorders which are rated as intrinsically safe
should be taken into these area. Section 9 discussed inspection safety
in more detail.
6-6
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REFERENCES AND ADDITIONAL READING MATERIAL
1. U.S. Environmental Protection Agency, "Portable Instruments User's Manual for
Monitoring VOC Sources," EPA-340/1-86-015, June 1986.
2. Joseph, G., and M. Peterson, "APTI Course SL417, Controlling VOC Emissions from
Leaking Process Equipment, Student Guidebook," EPA-450/2-82-015, August 1982.
3. Engineering Science, "Benzene Equipment Leak Manual," EPA-340/1-40-001, July, 1990.
4. Riggin, R.M., "Guidance Document on the Use of Portable Volatile Organic Compounds
(VOCs) Analyzers for Leak Detection," Report Prepared for USEPA contract 68-02-3487
(WA-18), Undated.
5. U.S. Environmental Protection Agency, "Guideline Series - Measurement of Volatile
Organic Compounds," EPA-450/2-78-041, September 1979.
6. Mclnnes, Robert G., et ah, "Guide for Inspection Capture Systems and Control Devices at
Surface Coating Operations, Final Draft," Report Prepared for USEPA Contract No.
68-01-6316, May 1982.
7. Ressl, R.A., and T.C Ponder, Jr., "Field Experience with Four Portable VOC Monitors,"
Report Prepared for USEPA Contract No. 68-02-3767.
8. Debbrecht, F J., "Comparative Techniques for the Quantitation of Fugitive Emissions,"
Presented at the 75th Annual Air Pollution Control Association Meeting, New Orleans,
Louisiana, June 1982.
6-7
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LECTURE 7
NSPS AND NESHAP EQUIPMENT LEAK Notes
RECORDS AND REPORTS
The required records and reports are essential elements for the
demonstration of the compliance efforts of a facility. It is important
that an inspector be extremely familiar with the reporting and record-
keeping requirements of the regulations. The evaluation of these
reports and the examination of on-site records are vital portions of
compliance determinations. This lecture describes the content of
required reports for NSPS and NESHAP regulations and introduces
examples. Recordkeeping requirements are also discussed.
REPORTING
NSPS
New Source Performance Standards for VOC equipment leaks Slide 7-1
include: Subpart W - Equipment Leaks of VOC in the Synthetic
Organic Chemical Manufacturing Industry; Subpart GGG - Equipment
Leaks of VOC in Petroleum Refineries; and Subpart KKK -
Equipment Leaks of VOC from On-shore Natural Gas Processing
Plants. All these NSPS standards refer directly to Subpart W for
reporting and recordkeeping requirements. Therefore, NSPS reporting
and recordkeeping as discussed in this lecture are those requirements
contained in Subpart W.
There are two types of NSPS reports. The first is the
notification of construction or reconstruction. This requirement is
contained in the NSPS General Provisions (40 CFR 60, Subpart A
§60.7) and requires that any owner or operator subject to an NSPS
furnish written notification of the date of construction or reconstruction
within 30 days after work begins.
In addition to the construction notification, the General
Provisions require:
• A notification of the anticipated date of initial startup of an
affected facility postmarked between 30 and 60 days before
the startup date.
7-1
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Notes
• A notification of the actual date of initial startup of an
affected facility within 15 days after such date.
• A notification of any physical or operational change to an
existing facility which may increase the emission rate of any
pollutant to which a standard applies, unless that change is
specifically exempted. This notice shall be postmarked 60
days or as soon as practicable before the change is
commenced.
Initial Semi-Annual Reports
Facilities are also required to submit semi-annual reports
beginning six months after the initial startup date, and every six months
thereafter. The content of the initial semi-annual report and the
subsequent semi-annual reports is somewhat different.
The initial semi-annual report must include an identification of Slide 7-2
the process unit, the number of valves in gas/vapor service or light
liquid service, the number of pumps in light liquid service, and the
number of compressors.
Valves, pumps, and compressors which are designated as no
detectable emissions should not be included in the totals listed in the
initial semi-annual report.
Semi-Annual Reports Slide 7-3
Semi-annual reports are required beginning six months after the
initial semi-annual report, and each six months thereafter. The
information which is required in the semi-annual report begins with the
process unit identification. This should coincide with the identification
in the initial semi-annual report. As discussed in Lecture 2, a
monitoring program must be established and adhered to by the plant
for valves, pumps, and compressors. When a leak is discovered, it must
be repaired within 15 calendar days, barring some unavoidable
circumstance. The semi-annual report must contain, on a monthly
basis, the total number of leaks which were detected and the number
of this total which were not repaired in the required 15 day period. In
each instance where a repair was delayed, the report should contain an
explanation of the delay. If the reason for the delay is that it could not
be repaired until a process unit shutdown, then the report should
indicate why a process unit shutdown was technically infeasible during
the reporting period. The report should then show the dates during
the reporting period when process unit shutdowns occurred. Also, if
7-2
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Notes
revisions to items reported in the initial semi-annual report have
occurred, these should be described and discussed.
Reference Volume 2-1.1 is an example of an NSPS semi-annual
report. This is one format of the semi-annual report. Reference
Volumes 2-1.6 through 2-1.12 are actually examples of NESHAP
reports but the formats shown could also be applicable to NSPS. As
these References illustrate, the format of these reports is not specified
in the regulations.
There are other reporting requirements contained in the NSPS Slide 7-4
regulations. The regulations contain two alternative standards for
valves, the allowable percentage of valves leaking and the skip period
leak detection and repair program. The first alternative specifies a two
percent limitation as the maximum percent of valves leaking within a
process unit, determined by an initial performance test and a minimum
of one performance test annually thereafter.
The second alternative standard specifies two skip-period leak
detection and repair programs. Under this option an owner or
operator can skip from monthly/quarterly monitoring to something less
frequent after completing a specified number of consecutive monitoring
intervals with the percentage of valves leaking equal to or less than 2.0
percent. Under the first skip program, after two consecutive quarterly
periods with fewer than two percent of valves leaking, an owner or
operator may skip to semi-annual monitoring. Under the second
program after 5 consecutive quarterly periods with fewer than two
percent of valves leaking, annual monitoring may be adopted. If an
owner or operator elects to comply with either of these alternative
standards, a report must be provided within 90 days before
implementing the provisions.
The General Provisions of the NSPS regulations require that the
owner or operator furnish EPA with a written report of the results of
any performance test. Performance tests are required for no
detectable emissions equipment and valves complying with an
alternative standard. They also may be required for closed vent
systems and control devices and equivalent means of emission
limitation. Information must be made available to EPA as may be
necessary to determine the operating conditions during the
performance tests. In addition, the NSPS requires that the owner or
operator notify the Administrator of the schedule for the initial
performance tests at least 30 days before conducting them.
7-3
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Notes
Finally, it should be recognized that, although NSPS is a federal
regulation, enforcement authority may be delegated from U.S. EPA to
the States. Reports would then be submitted to State agencies instead
of U.S. EPA.
NESHAP
There are three National Emission Standards for Hazardous Air Slide 7-5
Pollutants (NESHAPs) for equipment leaks which include Subpart F -
National Emission Standard for Vinyl Chloride, Subpart J - Equipment
Leaks (Fugitive Sources) of Benzene, and Subpart V - Equipment
Leaks (Fugitive Emission Sources). Each of these NESHAPs require
that an initial statement be submitted. All subparts require the
submittal of semi-annual reports. However, if less than 2 percent of
the valves for a vinyl chloride process unit are shown to be leaking by a
performance test, then these results must be submitted and a new
performance test conducted annually.
Initial Reports
The initial report contains two portions. The first is a written Slide 7-6
assertion that states the company will implement the standards, testing,
recordkeeping, and reporting requirements contained in the applicable
NESHAP. The second part is information regarding the equipment
subject to the regulation. This includes equipment identification
numbers and process unit identification for each source as well as a
description of the type of -equipment (for example, a pump or a
pipeline valve). Also, the percent by weight of volatile hazardous air
pollutant (VHAP) in the fluid at the equipment and the state of the
fluid (i.e. gas/vapor or liquid) is required. Finally, the report must
contain a description of the method of compliance to be utilized. The
initial report must also contain a schedule for subsequent reports.
All plants which were in existence on the effective date of
NESHAP standards were required to submit an initial report.
Therefore all existing facilities subject to the above referenced
standards should have already submitted an initial report. All new
plants are required to submit an initial report with the application for
approval of construction required by the general provisions of Part 61
(NESHAPs).
Reference Volume 2-1.2 is an example of an initial NESHAP
report which contains the required assertion along with a discussion of
the monitoring schedule. It also contains a list of points to be
monitored. Reference Volumes 2-1.3, 2-1.4, and 2-1.5 are portions of
7-4
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Notes
initial reports which contain a list of the equipment subject to the
regulation with the required information for each component.
Semi-Annual Reports
Six months after this initial report and each six months Slide 7-7
thereafter, the facility must submit reports. These semi-annual reports
are very similar to the NSPS semi-annual reports. They must contain
the process unit identification and the following information on a
monthly basis for each process unit.
• The number of valves, compressors, and pumps that were
detected leaking
• Of these valves, compressors, and pumps that were
detected leaking, the number which were not repaired
within 15 days.
• An explanation of why a repair was delayed. If the reason
for the delay was that a process unit shutdown is needed
before repair, then an explanation must be given why a
process unit shutdown was infeasible.
The report must also include the dates of all process unit shutdowns
during the six month reporting period and a discussion of any revisions
to the initial report.
Reference Volumes 2-1.6 through 2-1.12 are examples of
NESHAP semi-annual reports. As can be seen, each facility develops
and uses its own format for these reports. The regulations do not
specify the format of the reports, only the minimum requirements on
content. Specific items of note regarding these reports are as follow:
• Reference Volume 2-1.9 contains a pump which was not
repaired within the 15 day limit with an explanation of the
reason for delay. Although the pump was not repaired
within the required time period, the report clearly explains
the history of the problem pump. This history begins with
the initial leak detection and follows it through until a
successful repair was reported.
Attachment III of Reference Volume 2-1.9 also contains an
addition/deletion list which presents another format of the
required information describing equipment subject to the
NESHAP.
7-5
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Notes
• Reference Volume 2-1.10 contains a report of the
monitoring of difficult and unsafe to monitor valves.
As is the case for NSPS, the NESHAP allows: 1) the
designation of equipment subject to no detectable emissions limit
rather a leak detection and repair standard; 2) an alternative standard
based on the allowable percentage of valves leaking; and 3) an
alternative skip period leak detection and repair program. All three of
these require performance tests along with closed vent systems and
control devices. If a performance test was conducted within the 6
month reporting period, then the results of the test must also be
included in the semi-annual report.
Reference Volume 2-1.11 contains examples of annual no
detactable emissions testing of closed vent systems and valves and
updating equipment identification information.
There are certain other aspects of the reporting requirements of Slide 7-8
a NESHAP. The semi-annual reports must be submitted twice per
year beginning six months after the submittal of the initial report. The
initial report also must contain a schedule verifying the months when
these semi-annual reports will be submitted. The source must then
abide by this schedule unless it is amended in subsequent semi-annual
reports.
If an owner or operator of a facility wishes to comply with either
of tht alternative standards for valves (i.e. the allowable percentage of
valves leaking or the skip period leak detection and repair), they must
provide notification 90 days before implementation of either of these
programs.
There are certain instances described in the regulations where
an application for approval of construction/modification is not required.
These circumstances are:
• if a new source complies with the standards,
• if the new source is not part of the construction of a
process unit, and
• if all information required in the initial report is contained
in the next semi-annual report.
RECORDKEEPING
7-6
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Notes
The review of records at a facility is an important element of Slide 7-9
determining whether a facility is in compliance with the standards. The
NSPS and NESHAP fugitive leak regulations require that extensive and
detailed records be maintained on-site by the facility. The ensuing
discussion will highlight the recordkeeping requirements of these
regulations.
Several lists must be maintained in the records at a subject Slide 7-10
facility. These are:
• A list of identification numbers for all equipment subject to
the requirements.
• A list of the equipment identification numbers of the
equipment that are designated for no detectable emissions.
This designation must be signed by the owner or operator.
A compliance test is required for the designation of
equipment as no detectable emissions. Certain information
regarding each of these annual tests is to be retained. This
information includes the date of the compliance test, the
background level measured, and the maximum instrument
reading measured at the equipment.
• A list of equipment identification numbers for pressure
relief devices required to comply with the standards for
pressure relief devices in gas/vapor service.
• A list of identification numbers for equipment in vacuum
service.
If a closed vent system and a control device is used to control Slide 7-11
fugitive emissions, then records are required relating to this equipment.
These records must contain:
• detailed schematics, design specifications, and piping and
instrumentation diagrams
• dates and descriptions of any changes in the design
specifications
• a description of the parameter or parameters monitored to
ensure that a control device is operated and maintained in
conformance with their design and an explanation of why
that parameter was selected for monitoring
7-7
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Notes
• periods when the closed vent systems and control devices
are not operated as designed, including periods when a
flare pilot light does not have a flame
• dates of startups and shutdowns of the closed vent systems
and control devices
A dual mechanical seal system that includes a barrier fluid Slide 7-12
system is an alternative for reducing emissions from pumps and
compressors. In the instances where a dual mechanical seal system
with a barrier fluid system is used, the following information must be
included in the records: 1) the design criteria that indicates failure of
the seal system, the barrier fluid system, or both, 2) an explanation of
the choice of this design criteria, and 3) documentation of any changes
to this criterion and the reasons for the changes.
The records must also contain a list of identification numbers Slide 7-13
for valves that are designated as unsafe to monitor with: 1) an
explanation for this designation, and 2) the plan for monitoring each
valve. The same is true for those valves that are designated as difficult
to monitor.
For those valves complying with the skip period provisions, a Slide 7-14
schedule of monitoring must be kept on file along with a record of the
percent of valves found leaking during each monitoring period.
There are criteria which will allow a facility to be exempted Slide 7-15
from the NSPS or NESHAP requirements. If a facility claims an
exemption then it must maintain a log which contains information,
data, and analyses to support their exemption declaration.
For each compliance monitoring test conducted, a record Slide 7-16
detailing the results must be retained. This includes the monthly leak
monitoring for pumps and valves, as well as the annual no detectable
emissions monitoring for pumps, compressors, valves, and closed-vent
systems. This also includes any monitoring for alternative standards.
There are other non periodic circumstances which require Slide 7-17
compliance monitoring. A pressure relief device must be monitored
within 5 calendar days after a pressure release to confirm the
conditions of no detectable emissions. In the instance where a pump
or valve is in heavy liquid service, a pressure relief device is in light
liquid or heavy liquid service, or a flange or other connector is
suspected of leaking, this equipment must be monitored within 5 days.
If a leak is detected and a repair attempt executed, the component
7-8
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Notes
must be monitored to determine if the repair attempt was successful.
Records must be kept detailing the findings of all such monitoring tests.
If a leak is detected, the equipment must be identified as a Slide 7-18
leaking component. This is done by attaching an identification tag to
the leaking equipment. The tag must be weatherproof and readily
visible. A tag may be removed after the equipment has been repaired
and retested successfully, except for valves. The tag may only be
removed from a valve after it has been repaired and monitored for 2
successive months with no leak detected.
When a leak is detected, records regarding each leak must be Slide 7-19
kept and maintained for 2 years. For each leak detected, the following Slide 7-20
information must be recorded: the equipment ID number, the
instrument and operator identification numbers, and the date the leak
was detected.
The date of each repair attempt should be recorded along with
an explanation of the methods applied in each instance. If the leak
was corrected, then the date of the repair should be designated the
date of successful repair and entered in the log. If the repair is
unsuccessful, then it should be recorded that the maximum instrument
reading of the monitoring after the respective repair was above 10,000.
If a leak is not repaired during the 15 calendar days after it is
detected, "repair delayed" should be entered and the reason for the
delay discussed. If the reason for the delay is that the repair could not
be attempted until a process shutdown, then the person who made the
decision must sign the log. If process unit shutdowns occurred while
the leak remained unrepaired, the dates of these shutdowns must also
be recorded. Finally, the expected date of successful repair of the leak
should be entered for these delinquent leaks.
Reference Volume 2-1.13 shows an example leak inspection and
repair recordkeeping system. Another example form for this purpose
was contained as Attachment IV of Reference Volume 2-1.9.
To summarize, records must be kept for two years which contain
the identification of: 1) the leaking equipment, 2) the instrument
which recorded the leak, and 3) the instrument operator. It should
contain the dates of: 1) the leak detection, 2) each repair attempt, 3)
the expected repair completion, 4) the process unit shutdowns while
the leak remained unrepaired, and 5) the date of the successful repair.
For each unsuccessful repair, "above 10,000" should be recorded to
designate that the maximum instrument reading was greater than
7-9
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10,000 ppm (i.e., leaking). And finally, if the decision is made that the
repair must be delayed until a process shutdown, then the person
making that decision must sign the log.
Notes
SUMMARY
Reporting and recordkeeping requirements are vital to
determine compliance with a regulation designed to control VOC or
hazardous emissions from equipment leaks. For NSPS regulations,
there are two basic types of reports, the notification of construction
and the semi-annual reports. These semi-annual reports contain
information regarding the findings of the leak detection and repair
program. NESHAPs also require the submittal of semi-annual reports,
beginning with an initial report which must contain a listing of subject
equipment along with equipment type, the percent of volatile
hazardous air pollutant, the state of process fluid, and the method of
compliance. The semi-annual reports are very similar to the NSPS
semi-annual reports. There are alternative standards for both NSPS
and NESHAP which allow leak testing on an annual or "skip" basis for
equipment which has demonstrated to have a low propensity to leak.
The regulations require that extensive records be kept regarding
the identification of equipment. Specific records must be kept for
closed-vent systems and control systems, pumps and compressors,
valves, skip period valves, and compliance monitoring results. Records
are also required for equipment which is exempt from the regulation.
There-are precise procedures to be followed in the, case of an
equipment leak. These pertain to the marking of leaks and the
associated recordkeeping procedures.
In summary, it is extremely important that an inspector be
familiar with the reporting and recordkeeping requirements of the
regulations as this is a good indicator of the overall leak detection and
repair program as implemented at the facility.
Slides 7-21, 7-22
7-10
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LECTURES
IMPLEMENTATION DECISIONS AND GUIDANCE Notes
The fugitive emission regulations are a complex set of Sb'de 8-1
regulations. Implementing and enforcing these regulations require, at
times, additional guidance and understanding not provided in the
regulations themselves. In this lecture, information is presented on
past EPA guidance on questions that have been raised in implementing
these regulations. This information is drawn from EPA policy
memoranda on the Benzene Equipment Leak NESHAP.
In addition, this lecture presents suggestions on way that you, as
an inspector, can better enforce the regulations. This is not an
exhaustive list of suggestions. The areas discussed cover (1) the
relationship of information required to be reported or recorded to
determining compliance with the regulations and (2) determinations left
to the plant operator.
EPA POLICY MEMORANDA
This part of the lecture focuses on selected interpretation issues Slide 8-2
associated with the Benzene Equipment Leak NESHAP. The first item
listed in Slide 8-2 is more of a summary document of the rule, but
includes discussion of several enforcement issues. The other items in
Slide 8-2 are selected topics drawn from a number of EPA
memoranda, records of communications, and other correspondence,
which have been distributed. Other issues of interpretation are found
in these documents.
Enforcement Guideline S-28
This document was prepared to aid in the enforcement and
implementation of the benzene NESHAPs. The document summarizes
the benzene equipment being regulated under benzene equipment leak
NESHAP and the standards to which this equipment is subject, and
provides guidance on several issues of enforcement concern.
The following summarizes the document in outline form.
8-1
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Notes
Background
Four sources of benzene were originally proposed for
regulation:
• equipment leaks
• maleic anhydride plants
• ethylbenzene/styrene plants
• benzene storage vessels
The latter three were dropped as additional analysis led
EPA to conclude that the health risks and potential
reduction in the health risks were too small to warrant
regulation under Section 112.
EPA found that fugitive benzene emissions posed a
significant risk and should be regulated.
Introduction
Use of various equipment in industry and their potential to
leak.
Scope and Applicability
Identifies the equipment covered by the standards
Must be in benzene service
Exemptions
• coke by-product plants
• < 1,000 Mg/yr design production in use of benzene
Standards
Reviews the standards for each piece of covered equipment.
Equivalent Means of Emission Limitation
Summarizes procedure for applying for a determination of
equivalency.
8-2
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Notes
No Detectable Emissions
Summarizes equipment for which "no detectable emissions"
may be designated, compliance methods, testing, and
monitoring.
Reporting Requirements
Summarizes the reporting requirements (initial report, semi-
annual reports).
Recordkeeping Requirements
Summarizes recordkeeping requirements.
Compliance Issues
Determining percent benzene content.
Development of a criterion indicating system failure.
Development of written plans for monitoring unsafe-to-
monitor values and difficult-to-monitor values.
Selection of monitoring parameters to ensure control
devices are operated and maintained in conformance with
their designs.
Granting of waiver from a benzene standard for up to two
years.
Sewers
Issue:
Are sewers covered by Subpart V?
Guidance: Sewers and their vents are not covered by
Subpart V.
Oil/Water Separators
Issue: How are oil/water separators analyzed for weight
percent benzene? Some companies wanted to
determine the weight percent benzene for both the
hydrocarbon and water layers combined, which in
Reference 1
Reference 1
8-3
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Notes
some cases would exempt some separators via the
10 percent criteria.
Guidance: Hydrocarbon/water separators in the process can be
considered to be product accumulators. Since the
standard covers accumulators containing either 10
weight percent benzene liquid or 10 weight percent
vapor, the vapor in the headspace of separators
should be analyzed using the 10 percent criteria.
they are "in benzene service" (i.e., meet the 10
percent benzene criteria), they are subject to the
standards.
If
Storage Terminals
Issue: Are storage terminals considered "plant sites" as per
§61.110(c)(2)?
Guidance: Storage terminals are considered plant sites subject
to the Benzene Equipment Leak NESHAP unless
they can be exempted by virtue of either containing
no streams with 10 percent benzene or greater or
processing less than 1,000 megagrams (2.2 million
pounds) of benzene per year.
Use versus Purchase of Benzene
Issue 1: Section 61.110(c)(2) of Subpart J states: "Any
equipment in benzene service that is located at a
plant site designed to produce or use less than 1,000
megagrams of benzene per year is exempt from the
requirements of §61.112" (emphasis added). A
distillation operation circulated benzene in a closed
loop system in quantities greater than 1,000
megagrams per year, but the net usage and
recharge purchased totalled less than 15 megagrams
in each of two years. Is the term "use" limited to
the purchase or conversion that uses up the
benzene?
Guidance: The term "use" is meant to reflect the overall
quantity used in equipment at a facility and not the
consumption (conversion) rate of benzene at a
facility. The intent of this exemption was to exclude
Reference 2
Reference 3
8-4
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Notes
Issue 2:
such facilities as pilot plants and research and
development laboratories.
Is the "use" of benzene the actual use or the design
use of benzene?
Guidance: The design use is used in determining if a facility is
subject to the standard.
Welded Fittings
Issue:
Are welded fitting considered "connectors"?
Guidance: Welded fittings are "connectors," but they must be
fittings for pipes and equipment in benzene service.
Bypasses of Control Devices
Issue: A plant has a 'Vent recovery system" that receives
vapor streams from various plant processes,
including equipment in benzene service and
equipment not in benzene service. When this
system fails, certain bypass emissions systems are
used. How should a bypass of a control device by
treated?
Guidance: The system should be designed and operated to
achieve 95 percent control. When the system is not
operating, the plant must record this information,
but does not need to report it.
Product Accumulators
A number of situations have been identified for clarification as
to whether the equipment in question is considered to be a product
accumulator subject to the Benzene Equipment Leak NESHAP. The
background information document for the proposed standards states
that product accumulator vessels include overhead and bottoms
receiver vessels used with fractionation columns, and product separator
vessels used in series with reactor vessels to separate reaction products.
Reference 4
Reference 5
Reference 5
Issue 1: Are storage vessels considered to be product
accumulator vessels and thus subject to the Benzene
Equipment Leak NESHAP?
References 5, 6
8-5
-------
Notes
Guidance: Storage vessels are not included as part of the
product accumulator vessel unless they are surge
vessels in a process unit and no part of Subpart V
applies to them.
A storage vessel is differentiated from an
accumulator vessel by the following:
a. Accumulator vessels are typically located in
the process unit area (such as reflux drums,
product run-down tanks, etc.), whereas
storage vessels are isolated from the process
unit area.
b. Accumulator vessels usually have continuous
purges from their vents whereas storage
vessels do not.
Issue 2: Is a distillation column that bypasses through a
scrubber a "product accumulator vessel"?
Guidance: A distillation column is not covered. However, a
product accumulator vessel associated with this
column is covered.
Issue 3: A pressurized process upstream discharges a vapor
steam into a vapor surge tank (which is at
downstream pressure). The downstream line leads
to a vent recovery system. If the vent recovery
system is overloaded, back-pressure in the vapor
surge tank can approach the upstream pressure and
impair the effectiveness of the upstream process.
When the pressure in the tank gets too close to the
upstream pressure, a pressure control device
(sensing tank pressure) opens a control valve that
releases vapors (containing benzene) to the air. Is
this vapor surge tank considered a "product
accumulator vessel"?
Guidance: The tank that is described is probably a "product
accumulator vessel."
Reference 5
Reference 5
8-6
-------
Notes
Determination of "In Benzene or Vinyl Chloride Service
Issue 1:
Can units be classified as not "in benzene service"
without identifying each valve, flange, connector,
etc.
Guidance: Yes, but if the determination is made collectively
(groups of equipment), then each piece need not be
identified.
Issue 2: Should equipment "in benzene service" during start-
up and/or shut-down, but not during normal
operation, be classified as "in benzene service"?
Guidance: If the equipment is intended to operate "in benzene
service," it is covered. The decision on whether a
piece of equipment is "in benzene service" really
depends on how frequently the equipment is
operated "in benzene service."
Issue 3: A product accumulator vessel is filled almost
entirely with a liquid. The liquid contains 2 percent
benzene by weight, while the headspace contains
99 percent benzene. If the applicable limit of
10 percent is determined to mean either in the
liquid or vapor phase, the regulations would apply
because the vapor phase is over 10 percent.
However, if a mass balance is performed combining
both the liquid and vapor phases, the amount of
actual benzene by weight will not bring the total
weight percent up to 10 percent and the vessel will
not be covered. Is the vessel described above
considered to be in benzene service and thus
subject to the standard?
Guidance: A source "in benzene service" is defined as a piece
of equipment that either contains or contacts a fluid
(liquid or gas) that is at least 10 percent by weight.
The product accumulator vessel is the only piece of
equipment for which the regulations apply if either
the liquid or vapor phase is 10 percent benzene. In
the definition of product accumulator vessel
(§61.241), it is specifically mentioned that an
accumulator vessel is in VHAP (benzene) service if
the liquid or vapor in the vessel is at least 10
Reference 5
Reference 5
Reference 7
8-7
-------
Notes
Insulated Valves
Issue:
Guidance:
Plant Site
Issue:
percent by weight VHAP (benzene). This provision
is not included in the definition of any other
affected facility. For all these other facilities, the 10
percent by weight value is determined by a mass
balance only.
[Note: This distinction was made because the
accumulator vessels were the only pieces of
equipment that ESD believed would have
appreciable amounts of benzene in both the liquid
and vapor phases. All other equipment would have
benzene in only one phase.]
Most of the valves at a plant are insulated. Most
valves, therefore, are covered so that only the stem
shows. The rest of the valve is not accessible. How
should the plant treat insulated valves?
Insulated valves must comply with the standards for
valves (§61.242-7).
According to the B.F. Goodrich Company, their
Calvert City complex contains two separate and
distinct plant sites. Goodrich agrees that the
ethylene plant is subject to the Benzene Equipment
Leak NESHAP, but feels that the Carbopol plant
should not be. Goodrich claims that the Carbopol
plant is in a separate chain of command from the
ethylene plant, deals with a separate raw material
and product, and has received a separate
construction permit Additionally, the Carbopol
plant does not use benzene in a quantity
approaching 1,000 megagrams per year, since only
small quantities are consumed in the process each
year. The EPA Regional Office points out that
both the Carbopol and ethylene plants are part of
the same Calvert City complex and correspondence.
Is the Carbopol plant a separate plant site from the
ethylene plant?
Reference 5
Reference 8
8-8
-------
Notes
Guidance: Although "plant site" is not defined in the
promulgated rules, the term was defined in the
proposed benzene regulations as an entire refinery
or chemical plant, i.e., all benzene process units
under common ownership at the same geographical
location (46 FR 1169, January 5, 1981). Based on
this definition, the ethylene and Carbopol plants
should be considered to be the same plant site.
Review of the economic analysis for the Benzene
Equipment Leak NESHAP also supports this
interpretation - the pieces of equipment are in one
area and can be dealt with cost-effectively as a unit.
When similar situations arose during the economic
analysis for the standard, plants were considered to
be on the same plant site.
INSPECTION GUIDANCE
This part of the lecture presents guidance on certain aspects of
the regulations that require you, as an inspector, to apply additional
insight, effort, or knowledge in the enforcement of these regulations.
The first area discussed deals with information that is reported and
determining compliance with the regulations on the basis of that
information. The second area discussed deals with determinations that
are made by the plant operator in implementing the regulations.
Reporting/Enforcement Slide 8-3
The regulations require each owner or operator of an affected
facility to report certain information on the status of the components
subject to the regulations. The information that is reported may not be
sufficient to determine whether an owner or operator is complying with
the regulation. For example, an owner or operator is not required to
report repair data associated with pumps, compressors, and valves
(only the number that leaked are required to be reported). This makes
it more difficult to determine whether the owner or operator is
complying with the repair provisions of the regulations. Inspection of
the actual records are required to determine the actual compliance of
the plant with all aspects of the regulation.
Another example is the lack of recordkeeping and reporting
requirements for sampling connections and open-ended lines and
valves. Compliance determinations for these equipment can only be
8-9
-------
Notes
done by visual inspection at the plant. A walk-through of the plant
looking for uncapped (for example) open-ended lines may be necessary
to ensure that the plant is in compliance with the standard for open-
ended lines.
The main points for you to be made aware of are: (1) not
enough information is required to be reported for you to determine
compliance with the entire regulation from the reports, and (2) not
enough information is required to be recorded for you to determine
compliance with the entire regulation from the records. Some
inspection of the facility itself will be required.
Plant Operator Determinations Slide 8-4
The regulations allow plant operators to determine several items
in complying with these regulations. These items include: (1)
determining which components are in VOC, benzene, or vinyl chloride
service; (2) setting the criterion for "leaks" at pumps and compressors
with dual mechanical seals with barrier fluids; and (3) setting
monitoring system of operating conditions for control devices. As an
inspector, you should evaluate such plant determinations for their
reasonableness and accuracy.
If a component is designated as not in benzene service, for
example, it is excluded from the standards. As an inspector, you
should evaluate the procedure used to make that determination. Was
it made on the basis of engineering judgement or a test? If on
engineering judgement, is it clear from the process that this is an
accurate determination without question? If you are unfamiliar with
the specific plant operations, you may wish to contact other inspectors
who are familiar with that type of plant If the determination was
made on the basis of a test, was the test done property? Ask for a
copy of the test report and determine if procedures appeared to be
followed property. If you have doubts about the accuracy of the testing
(or the engineering judgement), request a sample and have the sample
tested independently.
A plant is required to design a criterion that indicates failure of
the seal system, the barrier fluid system, or both, for certain types of
pumps and compressors. It may be beyond the inspector's level of
experience or expertise to evaluate the criterion selected by the plant
operator and the sensor used to detect that criterion. The inspector
need not simply accept the plant's determination. To help make an
independent determination, the inspector could again talk with other
8-10
-------
Notes
inspectors who are familiar with similar systems or with vendors who
manufacture and install such systems.
The third example of plant operator set conditions involves the
plant owner monitoring the control devices to ensure that they are
operated and maintained in conformance with their design. For most
control devices, the operating parameters that should be monitored to
ensure conformance to their design are fairly uniform and
straightforward. However, there could arise situations in which a plant
operator .wished to monitor an "other-than-usual" parameter. The
inspector is encouraged to question such situations and talk with the
vendor of the control device for independent assurance.
In summary, there are several aspects of complying with these
regulations that are left up to the regulated. It is not necessary for the
inspector to simply accept the plant operator's determinations. The
inspector should arrive at an independent determination that what the
plant operator has decided upon is correct and acceptable. This may
require independent confirmation through additional testing or through
conversations with other inspectors or vendors.
8-11
-------
iCES
1. Record of Communication. Raymond Allen to Cliff Janey. October 23, 1984.
2. Record of Communication. Raymond Allen to Bill Davis. October 3, 1984.
3. Letter. A.M. Davis, EPA, to P.S. Advani, Texaco. August 20, 1984.
4. Record of Communication. Tom Diggs to Sabino Gomez. September 21, 1984.
5. Memorandum. F. Dimmick, OAQPS, to R. Meyers, SSCD. September 19, 1984.
6. Record of Communication. Raymond Allen to Tanya Murray. September 25, 1984.
7. Memorandum. E.E. Reich, EPA, to T.J. Maslany, EPA, Region III. February 8, 1985.
8. Memorandum. E.E. Reich, SSCD, to J.T. Wilburn, EPA Region IV. January 10, 1985.
8-12
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LECTURE 9
INSPECTION PROCEDURES Notes
Compliance determinations with equipment leak standards are Slide 9-1
not simple matters due to the complexity of these standards and the
many compliance options available to a facility. An equipment leak
standard may include hundreds, or even thousands of subject emission
points. This creates a difficult situation for an inspector attempting to
evaluate the compliance status of a facility.
Because of the complexities associated with these standards, it is
imperative that an inspection be conducted in a systematic fashion.
This section is intended to provide a guideline for these inspections. It
will present a method for conducting a fugitive equipment leak
inspection and provide an inspection checklist.
TYPES OF INSPECTIONS
An inspector can conduct a "Level 2" or "Level 3" type
inspection. A Level 2 inspection involves the determination of the
adequacy of the equipment leak detection and repair program and the
success of the plant in the implementation of this program. It also
involves the determination "of proper equipment design, usage, and
monitoring. This type of inspection is comprised of applicability
reviews, reports and records inspections, surveys of plant procedures,
surveys of equipment usage, a walk through of the facility, and the
observation of monitoring and testing by plant personnel. A Level 3
type inspection also involves all of these elements with the addition of
monitoring/testing conducted by the inspector.
There are varying opinions as to the effectiveness of a Level 3
inspection. In many instances, even if an inspector monitors a piece of
equipment and finds it leaking, this does not indicate a violation of the
standard. For example, consider the situation of an inspector carrying
an analyzer, testing a valve which is covered under the monthly
monitoring program and finding a leak. The presence of a leak at this
time does not indicate that the leak was present during the previous
monthly inspection, or that plant personnel would not have located and
repaired the leak during the next monitoring period.
9-1
-------
Notes
An inspector could check a representative sample of the
equipment and compare the findings with the history of the leak checks
conducted by the plant. If the inspector's test find a large percentage
of leaking valves, pumps, etc. and the plant's reports and records
consistently show very low percentages of leakers, then the monitoring
and testing procedures utilized by the plant should be examined closely.
Another manner of evaluating the screening procedures used by plant
personnel is to have plant personnel responsible for the program
monitor all the components in a process unit, or in a specific area of a
process unit, while the inspector follows and monitors the identical
equipment. After completion, the results of both evaluations should be
compared. If discrepancies exist, then the inspector should note this in
the inspection notebook and closely examine the technique of the plant
person who conducted the monitoring.
An inspector may carry his own monitor specifically to test
equipment which is designated as no detectable emissions or for those
plants utilizing the allowable percentage of valves leaking provision.
He or she could spot check no detectable emissions equipment. A
concentration of 500 ppm above background or greater indicates a
violation. It would also be a violation if greater than 2 percent of the
valves are found to be leaking for those process units complying with
the allowable percentage alternative standard. However, an inspector
should remember that the regulations require facilities complying by
either of these standards to conduct performance tests annually, or at
other times as requested by the Administrator. Therefore, the
inspector could simply request the plant to conduct such a test under
his or her supervision.
There are other reasons for conducting a Level 3 type
inspection at a facility. One is that the use of the portable VOC
analyzer helps an inspector develop a greater appreciation for some of
the field problems which are inherent in the screening programs. It
also helps to convince the source personnel that the inspector has an
active interest and concern with their screening program, and that the
inspector is competent in all aspects of the equipment leak regulations.
However, for the reasons discussed above, it is not usually
recommended that a Level 3 type inspection be conducted for
equipment leak regulations. Therefore the remainder of this section
will be dedicated to a procedure to be followed for a Level 2
inspection.
9-2
-------
Notes
INSPECTION ELEMENTS
There are four basic elements contained in an equipment leak
inspection program. These are a pre-inspection records search which
includes an applicability check and a review of submitted reports; an
on-site inspection which includes a records check, an equipment survey,
and an assessment of plant procedures; post-inspection data sorting;
and additional inspections. There are 5 questions which an inspector
should be able to answer at the conclusion of an inspection.
1. Are in-plant records being properly kept and semi-annual
reports being properly submitted?
2. When detected leaks are not repaired in the required time
frame, are the delays justifiable?
3. Can the plant's personnel demonstrate, in general terms,
the capability to carry out the work practice standards
required by the regulation?
4. Is all equipment in the facility that should be subject to the
standard being treated as such?
5. Does the facility's closed vent system and control device
(CVSCD) meet the requirements of the applicable
regulation?
Pre-inspection Records Search
Since any inspection requires labor and expense, minimizing the
inspection time spent in the plant is important. The inspector should
conduct a thorough search of the agency files on the facility to be
inspected. This will help determine the types of process units, the
number of process units, and the compliance history and trends of this
facility. The inspector should be as informed as possible about the
operation of these process units and the potential sources of emissions.
The more the inspector knows, the better he or she will be able to
communicate with plant personnel.
Sources subject to an equipment leak NSPS are required to
submit a notification of construction which gives general facility
information and an initial semi-annual report which contains
information regarding the quantity of subject equipment at the plant.
Sources subject to a NESHAP are required to submit an initial report
along with their application for approval of construction. This initial
Slide 9-2
Reference 1
Slide 9-3
9-3
-------
Notes
report contains general facility and process unit information as well as
a list of all subject equipment with details of individual components.
The inspector should review the initial reports and first determine if a
facility is claiming an overall exemption to the regulation.
There are provisions contained in the regulations which exempt
entire facilities. To review, Subpart W, the NSPS for equipment leaks
from SOCMI plants, contains the following exemptions:
• any affected facility that has the design capacity to produce
less than 1,000 Mg/yr is exempt;
• if an affected facility produces heavy liquid chemicals only
from heavy liquid feed or raw materials, then it is exempt;
any affected facility that produces beverage alcohol is
exempt; and
any affected facility that has no equipment in VOC service is
exempt.
Subpart J, the NESHAP for equipment leaks of benzene, also contains
facility exemptions which are as follows:
• any equipment in benzene service that is located at a plant
site designed to produce or use less than 1,000 megagrams
of benzene per year is exempt; and
• any process unit that has no equipment in benzene service is
exempt.
Other types of permits and reports, such as those for other air
regulations, and those for wastewater, hazardous waste, or toxic
substances permits should be obtained. Agency files should also be
examined closely to obtain any other compliance information,
correspondence, complaints, etc. regarding the facility. The
information contained in the initial reports should be compared with
these other sources of information to assess the consistency between
the details reported. This comparison should be conducted in all
situations, but especially where an exemption is being claimed.
NESHAP Section 61.11 allows EPA (or an equivalent State
agency with delegated NESHAP authority) to issue waivers of
compliance to subject facilities for up to two years after promulgation
of a new NESHAP. This waiver, in essence, is a schedule by which the
9-4
-------
Notes
source is required to achieve full compliance with a NESHAP. The
waiver includes intermediate dates with corresponding increments of
progress toward achieving full compliance. A key element of the early
inspections of a new NESHAP is to determine whether the subject
facilities are meeting the terms of their waiver schedules. Since all
current equipment leak NESHAPs became effective years ago, it is
unlikely that many, if any, facilities have waivers which are still
applicable. However, as new NESHAPs are promulgated (i.e.,
polymers), then this will be an important issue to consider.
It is important that the inspector keep detailed records for each
inspection. An inspection notebook should be initiated during the pre-
inspection time period so that all information is contained in a central
location for the entire inspection. The notebook may be used to form
the premise of the inspector's report and as evidence in legal
proceedings, therefore it is critical that the inspector substantiate the
facts with tangible evidence; i.e., pertinent observations, photographs,
copies of documents, descriptions of procedures, unusual conditions,
.problems and statements from facility personnel.
After determining that a facility is subject, the initial reports
should be evaluated for completeness. The initial semi-annual NSPS
report should contain process unit identification and descriptions, and
the number of subject valves, pumps and compressors. The initial
NESHAP report should contain a statement that the requirements of
the regulation are being implemented, along with process unit
identification, identification-of all subject equipment, equipment type,
percent of VHAP, the state of the fluid, and the method of
compliance. If the initial report, the notification of construction or
reconstruction, or the initial semi-annual report is incomplete, then the
inspector should document this in the inspection notebook.
NSPS and NESHAP sources are also required to submit semi-
annual reports. The inspector should evaluate the most recent semi-
annual reports for completeness and compliance with the requirements.
Recall that the following information should be contained in these
reports:
• process unit identification;
• number of valves, pumps, and compressors for which leaks
were detected;
• number of valves, pumps, and compressors for which leaks
were not properly repaired
Reference 1
Reference 2
Slide 9-4
Lecture 7
9-5
-------
Notes
• for each delayed repair, the facts that explain the delay and
where appropriate, why a process unit shutdown was
technically infeasible;
• dates of unit shutdown during the reporting period; and
• results of all performance tests conducted during the
reporting period (if applicable).
The inspector should document any deficiencies relative to omission of
required information. These semi-annual reports should be compared
with each other and with the initial or initial semi-annual reports to
determine the consistency of information. Any inconsistencies should
be noted and investigated further during the plant visit.
Reference Volumes 2-2.1, 2-2.2, 2-2.3, and 2-2.4 are example
reports which contain errors, inconsistencies, or suspicious areas
common for NSPS and NESHAP reports. Students should review
these reports and locate these instances. Reference Volume 2-2.5 is a
summary of many of these problem areas of the reports. After
completing this exercise, students should then refer back to the actual
reports contained in Section 7 (Reference Volumes 2-1.1 through 2-
1.12) and review these to determine if any problem or potential
problems exist.
During the review of the reports from the facility, any unclear
information or question areas should be highlighted so that plant
personnel can be questioned or plant records checked. A complete
and well organized list of all questions should be made in the
inspection notebook and carried on site during an inspection.
The overall plant compliance will be determined by a complete
inspection of records, equipment, and the leak detection and repair
program. From pre-inspection activities the inspector should already
possess a general understanding of the plant under investigation, the
processes employed, the products produced in addition to being
familiar with all applicable regulations and knowing what type of
information is required to determine compliance with each. This helps
to select those units suspected or detected as being compliance
problems. It is meaningful to gain an impression of the overall
situation through the review of the annual reports and other
information, but it is equally important that an inspector not prejudge a
facility based totally on its reports. The compliance determination
should be finalized only after the on-site inspection, the post-inspection
data review, and, if needed, follow-up inspections.
Ref. Vols. 2-2.1
through 2-2.5
Ref. Vols. 2-1.1
through 2-1.12
9-6
-------
Notes
On-Site Inspection
The Clean Air Act establishes the inspector's authorization to
enter a plant for the purpose of inspection. Upon presentation of
credentials, the inspector is legally authorized to enter into the plant to
inspect any monitoring equipment or methods, conduct leak screening
tests and access any records required to be maintained at the site.
Once the inspector has identified himself or herself and been
granted entry onto the plant site, an initial interview should be
conducted. The objective of the interview is to inform the facility
official(s) of the purpose of the inspection, the authority under which it
will be conducted, and the procedures which are to be followed. A
successful initial interview will aid in obtaining cooperation of the plant
officials in providing relevant information and assistance.
After the initial interview, the inspector should continue with the
inspection of the facility. This will include a review of the plant
records, an equipment survey, and an evaluation of plant procedures.
The recommended first step is the records review.
Records Review
The primary objective of the record inspections is to minimize
fugitive emissions through requiring adherence to the recordkeeping
requirements of the regulation. Records which are required to be kept
by the facility (and not reported) should be reviewed by the inspector
during- the on-site inspection. The inspector should determine what
information needs to be obtained to document compliance. In
particular, the inspector should identify missing information, incomplete
data or reports and inconsistencies in the available background
material and specifically seek to extract this information from on-site
facility reports for the purpose of making a compliance determination.
Likewise, if noncompliance is suspected, the inspector should
concentrate efforts on obtaining necessary documentation for
verification.
The first step in the records review should be to determine if
the records are complete according to the regulations. If a plant has
claimed an exemption for one or more process units the following
records are required:
• an analysis demonstrating the design capacity of the process
units;
Reference 2
Slide 9-5
9-7
-------
Notes
• an analysis demonstrating that equipment is not in VOC or
VHAP service, and
• a statement listing the feed or raw materials and products
from the affected facilities and an analysis demonstrating
whether these chemicals are heavy liquids or beverage
alcohol (NSPS only).
In this instance the inspector should evaluate the information contained
in the required records and verify that the facility or process unit
continues to meet the criteria for exemption.
For facilities with subject equipment, the following discussion
describes items which should be checked in the completeness review.
The plant should have the following information pertaining to all
subject equipment in permanent log:
• a list of identification numbers for equipment subject to the
standard;
• a list of identification numbers for equipment designated to
meet the "no detectable emissions" compliance option
including the owner/ operator's signature authorizing this
designation;
• a list of identification numbers for pressure relief devices
which are required to meet the "no detectable emissions"
standard;
• the dates of each "no detectable emissions" compliance test,
including the background level measured during each test
and the maximum instrument reading measured at the
equipment during each test; and
• a list of identification numbers for equipment in vacuum
service.
The plant should have the following information in a two year
log regarding leaks located on pumps, compressors, valves, PRVs in
liquid service, flanges, and other connectors:
• the instrument and operator identification numbers and the
equipment identification number;
Reference 2
9-8
-------
Notes
• the date the leak was detected and the dates of each
attempt to repair the leak;
• repair methods applied in each attempt to repair the leak;
• "above 10,000" if the maximum instrument reading after
each repair attempt is equal to or greater than 10,000 pprn;
• "repair delayed" and the reason for the delay if a leak is not
repaired within 15 calendar days after discovery of the leak;
• the signature of the owner or operator (or designate) whose
decision it was that repair could not be effected without a
process shutdown;
• the expected date of successful repair of the leak if a leak is
not repaired within 15 calendar days after discovery of the
leak; and
• the date of successful repair of the leak.
The plant should have the following information pertaining to
their closed vent system and control device (CVSCD) in a permanent
log:
• detailed schematics, design specifications, and piping and
instrumentation diagrams;
• the dates and description of any changes in the design
specifications;
• a description of the parameter or parameters monitors [see
61.242-ll(e)j to ensure that the control device is operated
and maintained in conformance with its design and an
explanation of why that parameter (or parameters) was
selected for monitoring;
• periods when the CVSCD is not operated as designed, (this
includes periods when vents that should be controlled are
bypassed to the atmosphere, a flare pilot does not have a
flame, etc.); and
• dates of startups and shutdowns of the CVSCD.
9-9
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Notes
The plant should have the following information pertaining to
unsafe and difficult to monitor valves in a permanent log:
• a list of all valves which are designated "unsafe to monitor"
with explanations of each valve; and
• a list of all valves which are designated "difficult to monitor"
with explanations of each valve;
For valves complying with the "skip period leak detection and
repair" compliance option, the plant should have a permanent log
containing:
• a schedule for monitoring; and
• the percent of valves found leaking during each monitoring
period.
Pumps and compressors that are equipped with a dual
mechanical seal system must have sensors to detect failure of the seal
system, the barrier fluid system, or both. For each pump or
compressor, the design criterion (or parameter chosen to monitor) and
an explanation of that criterion should be in a permanent log.
After determining the completeness of the records, a check for Slide 9-6
consistency and validity should follow. An inspector should take along
a few of the most recent semi-annual reports so that comparisons can
be drawn between the information contained in these reports and the
information in the on-site records. If any equipment is complying by an
option of the regulations which requires annual testing, then it is
advisable to bring semi-annual reports which contain test results. The
records for leaking pumps, compressors, and valves should be
compared with the numbers in the last several semi-annual reports.
Any inconsistencies between the reports and records should be noted.
If a facility uses one or more closed vent systems and control
devices to control emissions, then special records are required in this
instance. The records must contain a description of the parameter or
parameters monitored to ensure that control devices are operated and
maintained in conformance with their design and a description of the
reasons for this choice. The records must also contain design
specifications, instrumentation diagrams, etc. for the systems and
control device. Finally, the records must contain a log of periods when
the closed vent systems and control devices are not operated in
accordance with the design specifications.
9-10
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The test data pertaining to no detectable emissions equipment
or valves complying with percentage of valves leaking provision which
was reported should be compared with the test information contained
in the records. Again, any inconsistencies should be noted. A test for
a process unit complying with the two percent leakage that indicates
greater than two percent leakers is a violation. An instance where such
a test was conducted and not reported should be noted and
appropriate action taken.
Examination of the logs may reveal noncompliance due to
improper or inadequate recording procedures. Facilities are in direct
noncompliance under the following situations:
• failure to report leaks and dates of repairs;
• failure to report the reason for delaying repair of leaks past
an allotted time frame;
• failure to develop a schedule to observe visual emissions
from flares;
• failure to perform emission testing for control devices
(except in the case of flares); and
• failure to record periods when the control device is not
operating.
Equipment Survey
All equipment which is subject to the regulation should be
identified in the records, whether it is complying with an equipment
standard, a leak detection and repair program, or through the use of a
closed vent system and control device.
A major problem which confronts the inspector is determining if
equipment exists in the facility which is subject to the standard but is
not listed in the in-plant records and therefore is not being monitored
and/or does not meet the equipment specifications. This may be the
most difficult part of an inspection. One method of addressing this
problem is to request a process unit material balance with a
corresponding simplified flow diagram. This information could then be
reviewed in detail to determine if there appears to be equipment which
should be listed and is not. If such areas exist, then the on-site
inspection or follow-up inspection should address this issue.
Notes
Slide 9-7
Reference 2
Slide 9-8
9-11
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Notes
The NESHAP standards require that each subject component
be marked in such a manner that it can be distinguished readily from
other pieces of equipment. The inspector should spot check several
pieces of equipment contained in the listing to determine if they are
marked in a conspicuous manner.
The equipment which has been retrofitted with specified
controls or replaced with leakless equipment should be checked to
verify that they are in compliance with the appropriate equipment
standard. This evaluation should begin by identifying such equipment
during the records review. This consists of sampling connectors, open-
ended lines and valves, and product accumulators (NESHAPs only). It
also would consist of any equipment which is controlled by a closed
vent system and control device.
Several pieces of each type of equipment should be chosen as
candidates for spot checks to determine if they are designed and being
used as required. To review, sampling connectors are required to be
equipped with a closed-purge system or closed vent system, except for
in-situ sampling systems. Open-ended lines and valves are required to
be equipped with a cap, blind flange, plug, or a second valve. Product
accumulator vessels are required to be equipped with a closed-vent
system capable of capturing and transporting any leakage from the
vessel to a control device. Any equipment which is not in compliance
with the applicable requirements should be noted in the inspection
notebook.
Plant Procedures
An inspector should also evaluate several plant operating Slide 9-9
procedures during the inspection. Some of these procedures will be
indirectly observed while conducting other portions of the inspection,
and others will need direct attention to measure the appropriateness
and effectiveness. For example, during the reports and records
inspection, the inspector should develop a perception of the
effectiveness of the tracking system for monitoring and repairing leaks
and the system for recording and reporting data. The comparisons of
reports and records should give an idea of the interconnection of the
data and the efficiency with which it is transferred from the records to
the reports.
A key element of the facility inspection is evaluating the leak
monitoring program. This activity includes interviewing plant
personnel, observing facility personnel calibrate leak detection
equipment, and spot-checking a representative sample of equipment
9-12
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Notes
sources for leaks. This should be done by observing personnel perform
leak detection monitoring on each type of equipment subject to the
standard. By these observations the inspector verifies compliance with
leak detection program as well as demonstrates to the regulated
industry the agency's determination to actively pursue continuous
facility compliance with the regulations.
The timely scheduling and prompt execution of monitoring is
important, but equally important is the competency of the personnel
conducting the monitoring. There are several steps an inspector can
take to determine if the monitoring is being conducted in accordance
with the regulation. The inspector should first interview the plant
personnel that calibrate the portable hydrocarbon detectors and
conduct the required leak patrols. During this interview, the inspector
should discuss the applicable regulations, the plant procedures and
schedules for monitoring, the recording of monitoring results, general
information regarding VOC portable analyzers, requirements of
Method 21, and any other areas the inspector feels are appropriate.
The purpose of this interview is to determine if plant personnel have
received adequate training to perform the work practice standards
required by the regulation. ,
The instruments used to determine compliance of facilities must
be calibrated on a routine basis. The calibration precision tests,
response time and response factor tests reveal whether the instruments
are operating properly for the specific applications. The inspector
should witness the calibration procedures and note any deviations from
Method 21. The inspector should record the instrument response time,
the response factors, and calibration precision test.
As discussed in Lecture 5, a number of other factors can be
important such as: probe cleanliness, probe leakages, gas flow rates,
improper warm-up period, incorrect zero or meter adjustment. The
inspector should verify that the plant procedures include proper check-
out evaluations of the analyzer before use.
The inspector should also observe plant personnel performing
actual leak detection measurements. This observation can serve two
purposes. First it allows the inspector to evaluate the technique and
knowledge of Method 21, and second, it provides an opportunity to
spot check equipment. The plant personnel should be able to correctly
monitor fugitive emissions from all the equipment types at the plant
site. Additionally, the plant personnel should be able to correctly
determine background concentrations. Any deviations from the
Method 21 procedures discussed in Lectures 5 and 6 should be noted.
Lecture 5
Lectures 5, 6
9-13
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The spot checks should include monitoring of a few equipment
items for leaks. The inspector should concentrate the field monitoring
on the following:
• recently leaking devices;
• "no detectable emission" devices;
• closed vent systems and control devices (insure compliance
with minimum temperature, residence time, efficiency and
no detectable emissions);
• flares (no visible emissions as determined by Reference
Method 22)
• exempt devices (verify compliance).
Each dual mechanical seal system with barrier fluid system is
required to be equipped with a sensor that monitors the chosen criteria
to detect a system failure. This sensor must be checked daily or be
equipped with an audible alarm. The inspector should verify that the
sensor has an alarm which is working properly or that the sensors are
being monitored daily.
If a control device is being used to control VOC or VHAP
emissions, then records must be kept regarding this equipment. The
inspector needs to observe several items in this area. The first is the
identification of the control device and the manner in which the owner
or operator is monitoring its operation. Following are several questions
which should be answered for different types of control devices.
• What type of control device is used in the facility's CVSCD?
• What is the claimed control device efficiency?
• Is the efficiency measured (tested) or calculated? Obtain a
copy of any of these test results or calculations.
• For incineration devices, what is the combustion
temperature during the inspection (from the field or control
room)?
• Describe the control device and the critical parameters
which demonstrate compliance (e.g., adsorber pressure
Notes
Reference 3
Lecture 7
Reference 2
9-14
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Notes
drop/regeneration cycle time; scrubbing fluid flow
rate/pressure drop; final temperature leaving condenser).
• For flares, during normal operation what is the net heating
valve and exit velocity of the flaregas? Is the velocity and
net heating value of the flaregas'measured (tested) or
calculated? Obtain copies of these test results and/or
calculations. Check the flame indicating device (probably a
thermocouple readout) in the field or control room for
proper operation. Observe the flare for visible emissions.
The inspector should evaluate the parameters chosen and the
rationale for this selection to determine if these parameters are
appropriate to monitor proper operation for the type of control device.
The inspector should then review the monitoring data to
ascertain if the control device is being operated according to its design.
The records must also contain design specifications, instrumentation
diagrams, etc. so that this comparison can be drawn. The records are
to contain a log of periods when the closed vent systems and control
devices are not operated in accordance with the design specifications.
The duration and frequency of noncompliance episodes should be
noted. The inspector should compare his findings regarding such
periods (based on a review of the monitoring data) with the instances
recorded in the log. Any inconsistencies should be noted in the
inspection notebook.
Appendix B to
Ref. Vol. 2-3
POST-INSPECTION
Upon completion of the compliance inspection, the inspector
begins the final task of determining facility compliance. The inspector
should begin preparing the inspection report while all the events of the
inspection are still fresh in his or her mind. The inspector should
prepare the report before he or she conducts another leak detection
inspection. When two or more inspections are done at one time, it
becomes difficult to mentally separate one from another. The facility
data contained in the initial report, the semi-annual reports, as well as
results of the facility record review and the inspection provide the
inspector with the information to determine compliance with the
regulations. Additional information, elaboration or clarification may
come from the inspector's field notebook. If the inspector feels that it
is needed, letters may be issued or phone calls made requesting
additional information. The instance may occur where compliance
cannot be determined based on the initial inspection and subsequent
Slide 9-10
Reference 2
9-15
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Notes
information requests, and a return visit to the plant is necessary. These
follow-up type inspections should be abbreviated in nature and focus
on the question or problem areas.
The post-inspection process should begin by reviewing the
applicability determination to ensure that the facility as a whole and all
individual process units are properly classified. The equipment listings
shoujd also be reviewed.
There are two fundamental questions which an inspector should
consider during this post-inspection data sorting.
1. Is the recordkeeping system adequate to track monitoring,
leaks, and repairs?
2. Are the monitoring staff, equipment, and procedures
adequate?
The answers to these questions and rationale for these answers should
be contained in the inspection report. If the response to either of
these is no, suggestions should be made to proper plant personnel to
aid in correction of the existing problems.
The next phase of the post-inspection process is to write the Reference 2
inspection report. The report organizes and correlates all evidence
gathered during the inspection into a concise and useable format. The
report serves to record the procedures used in gathering data, gives
factual- observations and evaluations drawn in determining facility
compliance. The inspector's report will also serve as part of the
evidence for any enforcement proceeding or compliance-related follow-
up activities.
The inspection results should be organized in a comprehensive,
objective and accurate report. The recommended report elements are
listed below:
Introduction
• Compliance Status for Regulated Equipment
• Data
• Summary
After an inspection, the inspector should prepare for the next
inspection while the facility's processes are still fresh in his or her mind.
9-16
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This can be accomplished by preparing a list of items to be checked
and information to be reviewed or gathered during the next inspection.
Notes
There are several suggestions to be considered for additional
inspections. The pre-inspection preparation should basically be the
same for each inspection. The inspector should review all the
information contained in the facility's file including the intitial and
semi-annual reports. The semi-annual reports which have been
submitted since the last inspection should be reviewed most carefully.
The past inspection reports should also reviewed. If any items were
noted in these reports which required action by the facilty, then the
semi-annual reports should be examined with these specific areas in
mind. There also are items to consider regarding the on-site
inspection. Due to the large number of records which are required, it
may be impossible to review all records on each visit. If this is the
case, it is a good idea to spot check a different portion of the records
during each inspection. It is also suggested that the inspector check a
different area of plant by general walk-through and equipment spot-
checks in an effort to eventually cover the entire affected facility.
Slide 9-11
CHECKLIST REVIEW
Reference Volume 2-3 contains checklists designed to assist in
the inspection of a facility subject to the benzene NESHAP. Due to
the similarity of the NESHAP and NSPS standards, these checklists
could be easily modified for NSPS inspections. There are two
checklists, an inspection preparation checklist and an inspection
checklist.
The preparation checklist contains sections initial report review
for completeness and review of semi-annual reports. The inspection
checklist also includes facility information, a records checklist, a general
information gathering checklist, a table for recording vessels and non-
floating roof tanks not listed as product accumulator vessels, a benzene
stream identification table, and a field/control room inspection
checklist. If an inspector covers all areas in the checklist, this should
be an excellent foundation for an inspection.
It should be noted that no checklist can replace a
knowledgeable, experienced inspector. For this reason the inspector
should be extremely familiar with a great deal of background
information. To conduct an inspection where all compliance related
issues are uncovered, it is crucial that the inspector possess a good
Ref. Vol. 2-3
Reference 2
9-17
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Notes
working knowledge of the applicable standard and all associated
background information. This is especially true for equipment leak
standards due to the complexity and many compliance alternatives.
Therefore, an inspector should not depend on any checklist as an
inspection tool without first researching and understanding all aspects
of the regulations.
9-18
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REFERENCES AND ADDITIONAL READING MATERIAL
1. Joseph, G. and M. Peterson.; "APTI Course SL417, Controlling VOC Emissions from
Leaking Process Equipment, Student Guidebook," EPA-450/2-82-015; August 1982.
2. U.S. EPA, "Portable Instruments User's Manual for Monitoring VOC Sources,"
EPA-340/1-86-015, June 1986.
3. Engineering Science; "Benzene Equipment Leak Inspection Manual," EPA-340/1-90-001,
July 1990.
4. Mclnnes, Robert G. et. ah; "Guide for Inspecting Capture Systems and Control Devices at
Surface Coating Operations, Final Draft," Report Prepared for U.S. EPA Contract No.
68-01-6316; May 1982.
5. Weber, R.C. and K. Mims,; "Project Summary, Evaluation of the Walkthrough Survey
Method for Detection of Volatile Organic Compound Leaks," EPA-600/S2-81-073; July 1981.
6. Gordon, Robert J., et. al.; "Inspection Manual for Control of Volatile Organic Emissions
from Gasoline Marketing Operations," EPA-340/1-80-012; January 1990.
9-19
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LECTURE 10
INSPECTION SAFETY
Notes
INTRODUCTION
Safety is an important issue in equipment leak inspections. This
section discusses the importance of selecting safe portable VOC
monitors and recorders. Also the procedures for recognizing and
avoiding typical inspection hazards during leak screening tests are
addressed.
SELECTING AND USING VOC ANALYZERS
If an inspector is going to use a portable VOC detector, then it is
very important that the instrument itself be safe and that he or she is
knowledgeable of safe procedures for using the analyzer. Hazardous
locations are divided into three classes: Class I, Class II, and Class III. Reference 1
Each class is divided into two divisions (Division 1 or 2) according to
the probability that a hazardous atmosphere will be present; and also
into seven groups depending upon the type of hazardous material
exposure. Groups A through D are flammable gases or vapors, and
Groups £, F, and G apply to combustible or conducting dusts. Class I,
Division 1, Groups A, B, C, and D locations are those in which
hazardous concentrations of flammable gases or vapors may exist under
normal operating conditions. Class I, Division 2, Groups A, B, C, and
D locations are those in which hazardous concentrations of flammables
may exist only under unlikely conditions of operation.
Only instruments which are rated intrinsically safe for Class I, Slide 10-1
Division I and Division 2 areas should be used. Intrinsically safe
basically means that the instrument will not provide a source of ignition
if the instrument is used property. It is also important that instrument
recorders meet the same safety requirements as the instrument itself.
It is not difficult to identify instruments rated as intrinsically safe
because they will have a clearly marked seal.
Although an inspector need only look for the intrinsically safe seal, Slide 10-2
it is important that he or she be aware of the characteristics which
allow an analyzer to receive this classification. As mentioned earlier,
these areas have potentially flammable or explosive vapor
concentrations and it is extremely important that the analyzer not
produce any sparks which are exposed to the surrounding air. An
10-1
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Notes
intrinsically safe VOC analyzer must have encased battery packs,
encapsulated amplifiers, and have specially designed electrical circuitry.
In addition, flame ionization instruments must be equipped with flame
arresters.
Certain operating procedures and safety precautions must be Slide 10-3
observed when any portable VOC detection device is used. The first
thing that must be done is to read the operating and service manual
carefully before using the device in the field. Also, to maintain the
intrinsic safety which is built into certain detectors, it is important that
the operating and service manual be consulted before trouble-shooting
or servicing. The inspector should always check the instrument to
confirm that all protective features have not been disabled or removed.
Mixtures of hydrogen and air are flammable over a very wide range
of concentrations. Therefore, safety precautions should be taken when
refilling the hydrogen supply tank. This should be carried out in a safe
area to ensure that there are no sources of ignition.
Many typical hazards can be easily avoided if the inspector uses Slide 10-4
sound judgement during the leak screening tests. There are several
fundamental points which are worthy of reference. There may be
equipment (especially valves) in difficult or awkward locations. The
standards themselves recognize that this is a common situation as they
allow the designation of valves as difficult to monitor and unsafe to
monitor. A good rule is not to attempt to monitor equipment which is
located more than 6 feet above secure platforms.
There may be instances where an inspector needs to climb a
ladder. In these situations, the inspector should never attempt to hold
an analyzer while climbing or descending a ladder. Both hands must
be free for climbing.
The simple matter of walking around the plant while carrying the
instrument can present problems due to the possibility of slippery
surfaces. Care should be taken to select walkways which appear to be
secure. An inspector should not work in or around slick areas.
Equipment with rotating or moving parts which are left
unprotected present a safety hazard and special care must be taken to
keep support straps and other parts of the analyzer away from such
danger. Also a rigid probe should not be placed in contact with a
moving part such as a rotating pump shaft A short, flexible probe
extension tip may be used. Most pump shafts have shaft guards that
protect against entrapment in the rapidly rotating shaft. With some
10-2
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Notes
instruments, it is difficult to reach through the guard to the location of
the shaft and shaft seal. The guard should not be removed under any
circumstances, and those pumps without guards should be approached
very carefully. If there is any question concerning the safety of the
measurement, it should not be performed.
Another hazard which exists is the presence of extremely hot
equipment and hot exhausts. An inspector should avoid work in close
proximity to hot equipment, but be especially careful not to place the
umbilical cord from the detector on a heated surface such as a pipe,
valve, heat exchanger, or furnace.
INHALATION HAZARDS
The normal procedure for testing a leak at equipment is to place Slide 10-5
the probe within one centimeter of the equipment. This close location Lecture 6
is necessary because of the relatively poor capture effectiveness
inherent in the probe designs discussed in Lecture 6. This brings the
inspector into the immediate vicinity of the leak because of the short
length of most probes. If a leak is present, the VOC emission plume
concentrations are usually very high. Also, there are normally a
number of fugitive VOG leak sites around the equipment being
checked, thus increasing the possibility of contacting a high
concentration plume.
This can be especially hazardous because many of the fugitive VOC Slide 10-6
compounds have very poor warning properties therefore providing little
warning of their presence. Concentrations encountered for odor, taste,
and irritations are usually well above the permissible exposure Limits.
The risks are significant because some VOC compounds also have
serious toxic effects.
There are several steps which can be taken to avoid these Slide 10-7
inhalation risks. One is to survey areas before entering and refrain
from entering spaces with poor natural ventilation where high level
concentrations can collect. It may be helpful to identify risky areas by
leaving the instrument on while walking through the facility to detect
any intermittent fumigation from VOC leaks in the general area.
During the monitoring of a leak with a VOC analyzer, direct
contact with high concentrations can be partially avoided by not
standing directly above the portable analyzer probe. However, because
some contact is inevitable, respirator protection approved by plant and
agency safety officials should be worn at all times.
10-3
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Notes
A respirator is essential to inspector safety, but it is important to
realize that wearing a respirator does not eliminate all inhalation
hazards. Respirators have many limitations. Both cartridges and
canisters for organic vapor suffer breakthrough quickly and are not
equally effective for all types of organic compounds. The wearer
should consult published tables of relative breakthrough times before
using a particular respirator. Also, organic vapor air purifying
respirators become less effective when the air temperature and/or the
relative humidity increases. While monitoring a leak, the inspector
could exceed the safe operating range of the respirator and even
saturate the respirator cartridge. All screening tests should be
terminated when the concentration of organic vapor exceeds the
maximum safe concentration of his or her specific respirator.
In addition, many organic compounds emitted as fugitive leaks are
skin absorbable. Respirators do not provide any protection against
these materials.
The respirators may create an inhalation hazard of their own. If
the respirator face pieces have been sprayed by organic liquids and
decontamination of the face pieces is not complete, there may be
organics remaining. These face pieces should be carefully inspected for
remaining contamination before using. If there is a questions
concerning the adequacy of decontamination, the respirator should be
discarded.
Slide 10-8
Reference 2
Slide 10-9
GENERAL SAFETY POLICIES
There are other general safety policies which should be followed. Slide 10-10
The first is to plan ahead and obtain all necessary personal protection
equipment prior to leaving for the inspection site. Equipment should
not be borrowed from the plant. All the safety equipment, especially
respirators, should be checked to confirm that they are in good working
condition. The inspector should be aware of and conform to all
applicable plant and agency safety policies. If plant specific policies
are not known, then the inspector should take the time to discuss these
with plant personnel before proceeding through the plant,
Inspectors should not work alone. Because agency coworkers are Slide 10-11
rarefy present, the inspector should insist that someone from the plant
accompany him or her at all times to ensure that the inspector does
not inadvertently enter unsafe areas, to assist in the even of accidental
gas releases within the facility, to get help if the inspector is injured
and to provide general assistance and advice regarding safety.
10-4
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Notes
Inspectors rarely have the opportunity to acclimate to heat stress. Slide 10-12
Heat exhaustion and stroke can result from the physical exertion of
carrying the instruments and from exposure to hot process equipment.
Therefore, regularly scheduled breaks should be taken to drink.fluids
to reduce the risk of heat stress.
As noted in Lecture 6, it is best to calibrate the analyzer at a Slide 10-13
laboratory facility at the inspector's office before leaving. However, in Lecture 6
the event that this is not possible and compressed calibration gas
cylinders must be taken to the inspection site, then the inspector must
comply with all DOT regulations regarding the transport of such
cylinders.
10-5
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AND ADDITIONAL READING MATERIAL
1. Joseph, G., and M. Peterson, "APTI Course 81:417, Controlling VOC Emissions from
Leaking Process Equipment, Student Guidebook," EPA-450/2-82-015, August 1982.
2. U.S. Environmental Protection Agency, "Portable Instruments User's Manual for Monitoring
VOC Sources," EPA-340/1-86-015, June 1986.
3. Engineering Science, "Benzene Equipment Leak Manual," EPA-340/1-40-001, July, 1990.
10-6
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