GPT Code Compliance & Regulations 3 — Questions and Answers
Question 1: NFPA 54 defines 'medium pressure' gas piping as operating at pressures between:
- 0.5 psig and 2 psig
- 1 psig and 5 psig
- 2 psig and 200 psig (Correct answer)
- 5 psig and 125 psig
Correct answer: 2 psig and 200 psig
NFPA 54 classifies medium pressure piping as operating between 2 psig and 200 psig, requiring different material and joint standards than low-pressure systems.
Question 2: According to IFGC, which type of pipe is NOT approved for use inside a residential building for natural gas?
- CSST (corrugated stainless steel tubing)
- Black steel pipe
- Copper tubing (where not prohibited by the gas supplier)
- PVC plastic pipe (Correct answer)
Correct answer: PVC plastic pipe
PVC plastic pipe is not listed for interior residential natural gas service; only approved materials such as steel, copper, CSST, and certain PE pipes are permitted.
Question 3: A gas technician discovers that an existing installation uses galvanized steel pipe for natural gas. Under NFPA 54, this is:
- Acceptable if the system tests at 3 psig
- Prohibited because galvanizing reacts with certain gas odorants and can flake (Correct answer)
- Allowed only for exterior piping runs
- Permitted only on LP gas systems
Correct answer: Prohibited because galvanizing reacts with certain gas odorants and can flake
NFPA 54 prohibits galvanized steel for gas service because zinc can react with hydrogen sulfide odorants and flake scale into regulators and valves.
Question 4: Under IFGC, the required pressure test for new gas piping systems with an operating pressure not exceeding 14 inches WC must use a test pressure of at least:
- 1.5 times the operating pressure
- 3 psi for 30 minutes (Correct answer)
- 10 psi for 10 minutes
- 5 inches WC for 5 minutes
Correct answer: 3 psi for 30 minutes
IFGC requires new low-pressure systems to be tested at a minimum of 3 psig for at least 30 minutes with no pressure drop.
Question 5: Under 49 CFR Part 192, a gas distribution operator must provide each customer with a written description of:
- The local gas utility rate schedule
- Odorization procedures and odor threshold levels
- How to recognize and respond to a gas leak (Correct answer)
- The pipeline's MAOP and operating history
Correct answer: How to recognize and respond to a gas leak
49 CFR 192.616 requires operators to have a written public awareness plan that includes educating customers on how to recognize and respond to gas leaks.
Question 6: When is a bonding jumper required on CSST gas piping per NFPA 54 and manufacturer requirements?
- Only when CSST exceeds 50 feet in length
- Always, to provide electrical continuity and protect against lightning surge damage (Correct answer)
- Only in commercial buildings over three stories
- Only when CSST passes through the electrical panel room
Correct answer: Always, to provide electrical continuity and protect against lightning surge damage
NFPA 54 and all major CSST manufacturers require bonding to protect against arc damage from indirect lightning strikes.
Question 7: Which ASME standard governs the design and fabrication of gas appliance pressure regulators used in residential service?
- ASME B31.8
- ANSI Z21.80 / CSA 6.22 (Correct answer)
- ASME B16.5
- API 6D
Correct answer: ANSI Z21.80 / CSA 6.22
ANSI Z21.80 / CSA 6.22 is the standard for line pressure regulators used in gas appliance service.
GPT Code Compliance & Regulations 3
NFPA 54 defines 'medium pressure' gas piping as operating at pressures between: