SEPA
United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/S-95/017 August 1995
ENVIRONMENTAL
RESEARCH BRIEF
Pollution Prevention Assessment for a Manufacturer of
Stainless Steel Pipes and Fittings
Richard J. Jendrucko*, Julia A. Myers*, Todd M. Thomas', and
Gwen P. Looby"
Abstract
The U.S. Environmental Protection Agency (EPA) has funded
a pilot project to assist small and medium-size manufacturers
who want to minimize their generation of waste but who lack
the expertise to do so. In an effort to assist these manufactur-
ers Waste Minimization Assessment Centers (WMACs) were
established at selected universities and procedures were
adapted from the EPA Waste Minimization Opportunity As-
sessment Manual (EPA/625/7-88/003, July 1988). That docu-
ment has been superseded by the Facility Pollution Prevention
Guide (EPA/600/R-92/088, May 1992). The WMAC team at
the University of Tennessee performed an assessment at a
plant that manufactures stainless steel pipes and fittings. In
order to fabricate the pipes, stainless steel coil stock is pro-
cessed in tube mills to form continuous, cylindrical pipe. Seams
are welded and the pipe is cut to specified lengths. The pipes
are hardened in annealing furnaces and quenched. Then the
pipe ends are deburred and straightening is done as required.
The final step is acid pickling for cleaning and etching of the
pipes. The team's report, detailing findings and recommenda-
tions, indicated that the onsite treatment of pickling rinse water
generates a large quantity of hazardous sludge and that signifi-
cant cost savings could be realized by installing a sludge
drying oven to reduce the volume and weight of sludge shipped
offsite.
This Research Brief was developed by the principal investiga-
tors and EPA's National Risk Management Research Labora-
tory, Cincinnati, OH, to announce key findings of an ongoing
research project that is fully documented in separate report of
the same title available from University City Science Center.
"University of Tennessee, Department of Engineering Science and Mechanics.
"University City Science Center, Philadelphia, PA.
Introduction
The amount of waste generated by industrial plants has be-
come an increasingly costly problem for manufacturers and an
additional stress on the environment. One solution to the
problem of waste generation is to reduce or eliminate the
waste at its source.
University City Science Center (Philadelphia, PA) has begun a
pilot project to assist small and medium-size manufacturers
who want to minimize their generation of waste but who lack
the in-house expertise to do so. Under agreement with EPA's
National Risk Management Research Laboratory, the Science
Center has established three WMACs. This assessment was
done by engineering faculty and students at the University of
Tennessee's WMAC. The assessment teams have consider-
able direct experience with process operations in manufactur-
ing plants and also have the knowledge and skills needed to
minimize waste generation.
The pollution prevention opportunity assessments are done for
small and medium-size manufacturers at no out-of-pocket cost
to the client. To qualify for the assessment, each client must
fall within Standard Industrial Classification Code 20-39, have
gross annual sales not exceeding $75 million, employ no more
than 500 persons, and lack in-house expertise in pollution
prevention.
The potential benefits of the pilot project include minimization
of the amount of waste generated by manufacturers, and
reduction of waste treatment and disposal costs for participat-
ing plants. In addition, the project provides valuable experi-
ence for graduate and undergraduate students who participate
in the program, and a cleaner environment without more regu-
lations and higher costs for manufacturers.
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Methodology of Assessments
The pollution prevention assessments require several site vis-
its to each client served. In general, the WMACs follow the
procedures outlined in the EPA Waste Minimization Opportu-
nity Assessment Manual (EPA/625/7-88/003, July 1988). The
WMAC staff locate the sources of waste in the plant and
identify the current disposal or treatment methods and their
associated costs. They then identify and analyze a variety of
ways to reduce or eliminate the waste. Specific measures to
achieve that goal are recommended and the essential support-
Ing technological and economic information is developed. Fi-
nally, a confidential report that details the WMAC's findings
and recommendations (including cost savings, implementation
costs, and payback times) is prepared for each client.
Plant Background
This plant produces stainless steel pipes of various diameters
and lengths and custom-made pipe fittings. It operates over
6,240 hr/yr to produce nearly 30 million pounds of pipe annu-
ally.
Manufacturing Process
Raw materials used by the plant include coil and sheet metal
stock, solvent-based marking ink, and protective plastic end
caps. The two major operations in this plant, pipe and fitting
formation and acid pickling, are described in this section.
Pipe and Fitting Formation
Stainless steel coil and sheet stock is unloaded and stored
outdoors under protective cover. As it is needed, the coil stock
is moved indoors by forklift to one of six automatic tube mills
where the sides of unrolled metal strips are curled up to form a
continuous, cylindrical pipe. The seam of the resulting pipe is
SJee/ Coll and Sheet Slock
fused in an electric in-line welding operation. An abrasive saw
is used to cut the continuously-formed pipe to specified lengths;
sections of poorly welded pipe are cut away.
Stainless steel sheet stock is used to form custom products
such as T's, elbows, and reducers. The sheets are cut with a
band saw or plasma torch into smaller pieces and custom-
formed into final product shapes using various forming and
bending equipment.
All pipes and fittings are hardened in electric induction or gas
annealing furnaces. After annealing, the pipes are water spray-
quenched or quenched in a water-filled tank outdoors, depend-
ing on their size.
The roughened ends of the pipe are manually deburred with an
air grinder. Then the pipes are straightened as necessary and
transported to the acid pickling process.
Acid Pickling
All pipes and fittings are transported to the pickling process in
which an overhead crane is used to lower them into an acidic
pickle liquor solution which chemically cleans and etches the
black oxide surface layer resulting in a clean, rust resistant
pipe.
Each pipe is rinsed with water in one of two rinse tanks and is
then mounted on a wash rack and manually sprayed with water
in a second rinsing operation. After the pipes dry, they are
labeled with a solvent-based ink spray jet and protective plastic
caps are hammered onto the ends. The finished products are
stored outdoors until they are shipped to customers.
An abbreviated process flow diagram for pipe production is
shown in Figure 1.
Finished Pipe Shipped to Customers
Figure 1. Abbreviated process flow diagram for straight pipe manufacture.
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Existing Waste Management Practices
This plant already has implemented the following techniques to
manage and minimize its wastes:
• The polymer previously used by this plant as a flocculent in
the onsite wastewater treatment system has been replaced
by magnesium hydroxide in order to reduce the volume of
sludge generated and shipped offsite.
• An acid regeneration system has been installed to regener-
ate spent pickle liquor for reuse onsite.
Pollution Prevention Opportunities
The type of waste currently generated by the plant, the source
of the waste, the waste management method, the quantity of
the waste, and the annual waste management cost for each
waste stream identified are given in Table 1.
Table 2 shows the opportunities for pollution prevention that
the WMAC team recommended for the plant. The opportunity,
the type of waste, the possible waste reduction and associated
savings, and the implementation cost along with the simple
payback time are given in the table. The quantities of waste
currently generated by the plant and possible waste reduction
depend on the production level of the plant. All values should
be considered in that context.
It should be noted that the financial savings of the opportunities
result from the need for less raw material and from reduced
present and future costs associated with waste management.
Other savings not quantifiable by this study include a wide
variety of possible future costs related to changing emissions
standards, liability, and employee health. It also should be
noted that the savings given for each pollution prevention
opportunity reflect the savings achievable when implementing
each opportunity independently and do not reflect duplication
of savings that would result when the opportunities are imple-
mented in a package.
Additional Recommendations
In addition to the opportunities recommended and analyzed by
the WMAC team, several! additional measures were consid-
ered. These measures were not analyzed completely because
of insufficient data, implementation difficulty, or a projected
lengthy payback. Since one or more of these approaches to
pollution prevention may, however, increase in attractiveness
with changing conditions in the plant, they were brought to the
plant's attention for future consideration.
• Recycle waste packaging material that is currently shipped to
the municipal landfill.
• Periodically renew the filter press cloths that have lost the
maximum potential to pass clean water from the wastewater
treatment sludge.
• Modify material handling procedures in order to remove
metal shavings that have fallen inside the pipes during the
mill process prior to the acid pickling process. Implementa-
tion of this measure will lead to reduced generation of
hazardous sludge.
• Remove pipe surface oxide flakes in a high-pressure spray
wash orwith mild mechanical abrasion to reduce the quantity
of flakes carried over into the pickling tanks.
This research brief summarizes a part of the work done under
Cooperative Agreement No. CR-819557 by the University City
Science Center under the sponsorship of the U.S. Environmen-
tal Protection Agency. The EPA Project Officer was Emma
Lou George.
Table 1. Summary of Current Waste Generation
Waste Generated
Packaging and protective barrier waste
Leaked and spent lubricating oil
Spent abrasive saw blades
Stainless steel scrap
Oxidized metal flakes and metal dust
Quench water
Damaged plastic end caps
Pickling rinse water
Wastewater treatment sludge
Miscellaneous solid waste
Source of Waste
Receipt and storage of raw materials
Machining
Cutting of pipe
Machining and cutting of pipe
Annealing, debum'ng, and cutting
Quenching of pipes following annealing
Packaging of finished product
Acid pickling of product
Onsite treatment of wastewater
Various plant operations
Waste Management Method
Shipped to municipal landfill
Shipped to fuels blending program
Shipped to municipal landfill
Sold to scrap recycler
Shipped to special landfill
Sewered to POTW
Shipped to municipal landfill
Treated in onsite WWTP;
sewered to POTW .;
Shipped to hazardous waste landfill
Shipped to municipal landfill
Annual Quantity
Generated (Ib/yr)
7,500
8,540
5,200
700,000
30,000
49,800
130
84,598,000
1,560,000
1 35,000 cu ft?
Annual Waste
Management Cost
$01
5,980
01
-164,300
(net revenue received)
15,810
40
0'
89,100
265,370
26,990
' Included in annual waste management cost for miscellaneous solid waste.
2lncludes specific quantities given for packaging and protective barrier waste, spend abrasive saw blades, and damaged plastic
end caps. The majority of this waste stream is cardboard waste.
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Tebla Z Summary of Recommended Pollution Prevention Opportunities
Annual Waste Reduction
Pollution Prevention Opportunity
Waste Reduced
Quantity (Ib/yr)
Percent
Net Annual Implementation Simple
Savings Cost Payback (yr)
Install a propane-fired sludge drying oven to reduce Wastewater
tha vohma and weight of the sludge that is general- treatment sludge
odln the onslta wasiewater treatment system and
shipped olfsilB.
Utilize a trash compactor to reduce the volume of Miscellaneous
municipal trash shipped olfsite, thereby reducing solid waste
disposal costs.
Remove tha poor quality length of each coil of raw nfa
material prior to forming in the mills. Currentprac-
tica is for tha entire length of raw material to under-
go tha normal forming and welding operations, re-
gardtoss of the quality. The current procedure leads
to unnecessary expenditures of welding gases,
worker labor, and energy.
928,200
60
Automate the addition of caustic to the wastewater
treated In the ensile wastewater treatment plant In
order to reduce caustic purchases and reduce
labor costs.
nfa
$141,150
12,810
9,300
15,000
0.5
1.2
12,620
12,600
1.0
1A significant volume reduction would occur.
United States
Environmental Protection Agency
National Risk Management Research Laboratory (G-72)
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/S-95/017
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