For LP-Gas installations, a ______ differential of 125 psig is allowed by Underwriters Laboratories, Inc. listing and NFPA 58.

For LP-Gas installations, a ______ differential of 125 psig is allowed by Underwriters Laboratories, Inc. listing and NFPA 58.

• A. Minimum
• B. Maximum
• C. Nominal
• D. Average

Answer: (B)

A safety cap on how much pressure can be lost across LP-gas system components is what the standard is testing. The 125 psig figure is the upper limit allowed by UL listing and NFPA 58, so the term that fits is the maximum differential. This matters because it sets a ceiling for pressure drop across regulators, valves, and piping, ensuring the equipment can operate safely within tested conditions. If the actual differential stays at or below this limit, the installation remains within code and listing requirements. For example, an upstream pressure of 200 psig with downstream at 75 psig gives a 125 psig differential, which is within the limit; exceeding that would go beyond what the listing allows.

A safety cap on how much pressure can be lost across LP-gas system components is what the standard is testing. The 125 psig figure is the upper limit allowed by UL listing and NFPA 58, so the term that fits is the maximum differential. This matters because it sets a ceiling for pressure drop across regulators, valves, and piping, ensuring the equipment can operate safely within tested conditions. If the actual differential stays at or below this limit, the installation remains within code and listing requirements. For example, an upstream pressure of 200 psig with downstream at 75 psig gives a 125 psig differential, which is within the limit; exceeding that would go beyond what the listing allows.