G33 Master Gas Pipe Fitter Exam
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. Which of the following is the primary purpose of a gas pressure
regulator?
A. To filter contaminants in gas
B. To increase gas pressure
C. To reduce and stabilize gas pressure
D. To measure gas flow
The regulator’s job is to lower high incoming pressure to a safe, usable
level and keep it steady despite flow changes.
2. What is the minimum clearance required between a gas meter and
an ignition source per typical code?
,A. 6 inches
B. 18 inches
C. 36 inches
D. 48 inches
Gas codes require a safety buffer so any ignition source is not too close
to a meter; 18″ is standard in many jurisdictions.
3. Which material is most commonly used for natural gas piping inside
residential buildings?
A. PVC
B. Black steel
C. Copper
D. Aluminum
Black steel pipe is preferred for gas because of its strength and
compatibility.
4. What tool is used to cut threaded steel gas pipe?
A. Hacksaw
B. Reciprocating saw
,C. Pipe cutter/wheel
D. Angle grinder
A proper pipe cutter designed for steel produces straight, clean cuts for
threading.
5. Thread sealant used on gas pipe threads should be:
A. Oil-based
B. Water soluble
C. Approved for gas service
D. Silicone only
Only sealants tested and approved for gas prevent leaks and chemical
incompatibilities.
6. What is the typical thread standard for gas piping fittings?
A. BSPT
B. NPT
C. UNF
D. ACME
, National Pipe Thread (NPT) is tapered and standard in gas piping in the
U.S.
7. A gas shut-off valve must be installed:
A. Only at the meter
B. On every branch line
C. At the appliance and at the entrance to the building
D. At the regulator only
Valves must isolate both building service and individual appliances for
maintenance/safety.
8. Pressure testing of a newly installed gas line should be done using:
A. Propane
B. Air over 15 psi
C. Inert test medium, typically air or nitrogen at code-allowed
pressure
D. Water
Codes prohibit using combustible gases for tests; air/nitrogen at
specified pressure is safe and detectable by gauge.
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. Which of the following is the primary purpose of a gas pressure
regulator?
A. To filter contaminants in gas
B. To increase gas pressure
C. To reduce and stabilize gas pressure
D. To measure gas flow
The regulator’s job is to lower high incoming pressure to a safe, usable
level and keep it steady despite flow changes.
2. What is the minimum clearance required between a gas meter and
an ignition source per typical code?
,A. 6 inches
B. 18 inches
C. 36 inches
D. 48 inches
Gas codes require a safety buffer so any ignition source is not too close
to a meter; 18″ is standard in many jurisdictions.
3. Which material is most commonly used for natural gas piping inside
residential buildings?
A. PVC
B. Black steel
C. Copper
D. Aluminum
Black steel pipe is preferred for gas because of its strength and
compatibility.
4. What tool is used to cut threaded steel gas pipe?
A. Hacksaw
B. Reciprocating saw
,C. Pipe cutter/wheel
D. Angle grinder
A proper pipe cutter designed for steel produces straight, clean cuts for
threading.
5. Thread sealant used on gas pipe threads should be:
A. Oil-based
B. Water soluble
C. Approved for gas service
D. Silicone only
Only sealants tested and approved for gas prevent leaks and chemical
incompatibilities.
6. What is the typical thread standard for gas piping fittings?
A. BSPT
B. NPT
C. UNF
D. ACME
, National Pipe Thread (NPT) is tapered and standard in gas piping in the
U.S.
7. A gas shut-off valve must be installed:
A. Only at the meter
B. On every branch line
C. At the appliance and at the entrance to the building
D. At the regulator only
Valves must isolate both building service and individual appliances for
maintenance/safety.
8. Pressure testing of a newly installed gas line should be done using:
A. Propane
B. Air over 15 psi
C. Inert test medium, typically air or nitrogen at code-allowed
pressure
D. Water
Codes prohibit using combustible gases for tests; air/nitrogen at
specified pressure is safe and detectable by gauge.
