Which organizations are cited as allowing a 125 psig differential for LP-Gas installations?

• A. Underwriters Laboratories, Inc. listing and NFPA 58
• B. OSHA
• C. EPA
• D. ANSI

Answer: (A)

Understanding which standards bodies authorize a 125 psig differential in LP-Gas installations helps you know where to look for approved installation practices. The 125 psig differential is an allowance specified by the combination of NFPA 58, the code for LP-Gas storage and handling, and UL listing, which provides third-party safety certification for equipment. NFPA 58 sets how systems should be designed and installed, including acceptable pressure differentials between components to keep operation safe. UL listing confirms that the equipment—tanks, regulators, valves, piping—meets those safety and performance requirements. Together, they establish that a 125 psig differential is an approved parameter for LP-Gas installations. OSHA, EPA, and ANSI regulate and publish other safety, environmental, or consensus standards, but they do not specifically authorize this differential.