United States Office of Solid Waste EPA 540-F-14-001
Environmental Protection and Emergency Response January 2014
Agency (5104A) www.epa.gov/emergencies
INTERIM CHEMICAL ACCIDENT PREVENTION ADVISORY
Design ofLPG Installations at Natural Gas Processing Plants
The U.S. Environmental Protection Agency (EPA) is concerned that some natural
gas processing plants that store and process liquefied petroleum gas (LPG) may
not be designed in accordance with applicable industry standards and codes.
When undertaking compliance monitoring activities at such natural gas processing
plants, EPA considers whether facilities are designed in accordance with
recognized and generally accepted good engineering practices, including
applicable standards and codes, in determining compliance with the requirements
of the risk management provisions of section 112(r) of the Clean Air Act, 42
U.S.C. §7412(r), and the Chemical Accident Prevention Provisions of 40 C.F.R.
part 68. This interim advisory is being issued to raise industry awareness of codes
and standards that may be applicable at such facilities. EPA may issue a final
national advisory on this subject after receiving additional stakeholder feedback.
EPA inspectors have conducted inspections at a number of newly constructed
natural gas processing plants. EPA inspectors have been advised and have
verified that some plants have been constructed in accordance with National Fire
Protection Association 58, Liquefied Petroleum Gas Code (NFPA 58). While
compliance with NFPA 58 is consistent with good engineering practices, we note
that NFPA 58 does not apply to natural gas processing plants and advises that
additional, more specific industry standards than NFPA 58 would apply. See
NFPA 58, section 1.3.2 (2) ("This code shall not apply to natural gas processing
plants, refineries, and petrochemical plants."); see a/so NFPA 58, LP-Gas
Handbook, at section 1.3.2 (design and operational features for natural gas
processing plants are more restrictive). Other codes and standards may also need
to be followed in order to achieve the level of protectiveness recognized in the
industry as good engineering practice.
In particular, one widely recognized standard for the design of LPG installations at
natural gas processing plants is American Petroleum Institute 2510, Design and
Construction of Liquefied Petroleum Gas (LPG) Installations (API 2510) and its
companion document API 251OA, Fire Protection Considerations for the Design
and Operation of LPG Storage Facilities (API 251 OA). Section 1 of API 2510 (7th
and 8 Editions) states: "This standard covers the design, construction, and
location of liquefied petroleum gas (LPG) installations at marine and pipeline
terminals, natural gas processing plants, refineries, petrochemical plants, or tank
farms. This standard covers storage vessels, loading and unloading systems,
piping, or and related equipment." Earlier editions of API 2510 similarly define the
scope of the document to include natural gas processing plants. API 2510
requires wider spacing of LPG tanks from loading racks and other tanks than does
NFPA 58; API 2510 also requires adequate spacing of equipment at natural gas
processing plants not addressed in NFPA 58.
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Interim Chemical Accident Prevention Advisory January 2014
Other standards or guidance documents that may be applicable to LPG
installations, natural gas processing plants, wells and associated equipment
include but are not limited to:
• API Standards: 6A, 12R1, 12F, 12J, 12K, 12GDU, 51R, 54, 74, 75L, 76,
500, 505, 510, 521, 570, 576, 650, 618, 653, 752, 753, 2000, 2003, 2510,
251OA, HF1, HF2, HF3
• NFPA Standards: 15, 30, 70, 497
• American Society of Mechanical Engineers: A13.1, B31.3, B31.4, B31.8
• International Fire Code and Mechanical Code
• International Organization for Standardization: 13631
• Steel Tank Institute: SP001 -00
Implementing the correct industry standards is important to ensure adequate
protection from accidental releases to the air. The API 2510 and 251 OA
standards, which are directly applicable to LPG installations at natural gas
processing plants, contain different, more protective design criteria than the NFPA
58 standard for several parameters, including the distances between LPG tanks
and other equipment and the spacing between adjacent LPG tanks. In addition,
NFPA 30 and API 2000 require sufficient venting, under normal and emergency
conditions, for atmospheric aboveground storage tanks storing flammable liquids
(such as condensate) to prevent tank over-pressurizations from fire exposure at
the applicable facilities including those processing natural gas. Storage tanks
containing flammable liquids may also require secondary containment in
accordance with NFPA 30, and possibly the Spill Prevention, Control and
Countermeasure (SPCC) regulations at 40 C.F.R. part 112 and state or local
regulations.
When designing natural gas processing plants, owners and operators of these
plants should be cognizant of API 2510 and other applicable and widely
recognized industrial codes and standards. The codes and standards discussed in
this advisory are sources for establishing the level of design engineering
protectiveness that is recognized and generally accepted in the industry. Such
recognized good engineering practices also should be considered at bulk plants
or distributors that also are natural gas processing plants; industry standards not
referenced in state regulations may nevertheless be applicable to the design and
maintenance of a safe facility.
EPA is accepting comments on this interim advisory until July 31, 2014. To submit
comments or questions, please send an email to: LPG.interim.advisory@epa.gov.
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