GPT Code Compliance & Regulations 2 — Questions and Answers
Question 1: Under NFPA 54, what is the minimum clearance required between a gas appliance and combustible material?
- 1 inch
- As specified by the appliance manufacturer's listing (Correct answer)
- 6 inches
- 12 inches
Correct answer: As specified by the appliance manufacturer's listing
NFPA 54 requires clearances to combustibles to follow the appliance manufacturer's listed and labeled instructions.
Question 2: Which federal agency enforces pipeline safety regulations for gas distribution systems under 49 CFR Part 192?
- EPA
- OSHA
- PHMSA (Correct answer)
- CPSC
Correct answer: PHMSA
The Pipeline and Hazardous Materials Safety Administration (PHMSA) enforces 49 CFR Part 192 for natural gas pipeline safety.
Question 3: When a gas line passes through a foundation wall, NFPA 54 requires the pipe to be:
- Welded at both sides of the wall
- Sleeved to allow movement and sealed against gas entry (Correct answer)
- Painted with corrosion-resistant coating only
- Supported with a pipe hanger on each side
Correct answer: Sleeved to allow movement and sealed against gas entry
NFPA 54 requires a sleeve through foundation walls so the pipe can move and the annular space is sealed to prevent gas migration.
Question 4: According to NFPA 54, gas piping installed in concealed spaces must be:
- Schedule 80 pipe only
- Pressure tested after concealment at 10 psi
- Free of unions and accessible fittings (Correct answer)
- Wrapped with fire-resistant tape
Correct answer: Free of unions and accessible fittings
NFPA 54 prohibits unions, bushings, and right-and-left couplings in concealed locations to prevent gas leaks in inaccessible areas.
Question 5: What is the primary purpose of the 'maximum allowable operating pressure' (MAOP) designation under 49 CFR Part 192?
- To determine pipe wall thickness only
- To set the upper pressure limit for safe pipeline operation (Correct answer)
- To calculate the gas flow rate capacity
- To establish the testing frequency schedule
Correct answer: To set the upper pressure limit for safe pipeline operation
MAOP is the highest pressure at which a pipeline segment may be operated in compliance with 49 CFR Part 192.
Question 6: Under ICC IFGC, a sediment trap (drip leg) must be installed in the gas supply line to an appliance:
- Only on commercial appliances
- Upstream of the appliance shutoff valve (Correct answer)
- Downstream of the appliance pressure regulator
- Only when the appliance uses LP gas
Correct answer: Upstream of the appliance shutoff valve
The IFGC requires sediment traps upstream of the appliance shutoff valve to catch debris before it reaches control valves.
Question 7: Which document serves as the primary model code adopted by most US states for residential gas piping installation?
- API 1104
- 49 CFR Part 192
- IFGC / IRC Chapter 24 (Correct answer)
- ASME B31.3
Correct answer: IFGC / IRC Chapter 24
The International Fuel Gas Code (IFGC) and IRC Chapter 24 are the primary model codes adopted by states for residential gas piping.
GPT Code Compliance & Regulations 2
Under NFPA 54, what is the minimum clearance required between a gas appliance and combustible material?