Massachusetts Master Gas Fitter Exam
Practice Test Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A Instant Download
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1. What is the minimum distance a natural gas meter must be installed from
an ignition source in Massachusetts?
A. 6 inches
B. 12 inches
C. 18 inches
D. 12 inches
Rationale: Massachusetts code requires natural gas meters to be at least
12 inches from ignition sources to prevent fire hazards.
2. What is the primary purpose of a drip leg in a gas piping system?
A. To reduce pressure
B. To collect moisture and debris
C. To regulate gas flow
D. To vent excess gas
Rationale: A drip leg (sediment trap) collects moisture and debris to
protect downstream equipment from contamination.
3. What type of piping is typically prohibited for interior natural gas
distribution in Massachusetts?
, A. Black steel
B. CSST
C. PVC
D. Copper with approved fittings
Rationale: PVC is not permitted for interior natural gas distribution due to
fire and pressure hazards.
4. Which gas pressure is typically considered "low pressure" for residential
natural gas systems?
A. 1 psi
B. 0.5 psi or less
C. 2 psi
D. 5 psi
Rationale: Residential natural gas systems usually operate at low pressure
(0.5 psi or below).
5. What is the required minimum clearance for a gas appliance vent terminal
from a window or door?
A. 3 feet
B. 12 inches
C. 6 inches
D. 24 inches
Rationale: Massachusetts code requires vent terminals to be at least 12
inches from windows, doors, or openings to prevent backdrafting or
ignition of flammable vapors.
6. Which type of joint is preferred for black steel gas piping?
A. Compression
B. Soldered
C. Threaded
D. Flanged
Rationale: Threaded joints are standard for black steel piping because
they provide a strong, leak-resistant seal.
, 7. What is the maximum allowable pressure drop in a natural gas distribution
system from meter to appliance?
A. 0.5 psi
B. 0.5 inch WC
C. 1 psi
D. 1 inch WC
Rationale: Pressure drop should not exceed 0.5 inches water column for
safe and efficient appliance operation.
8. What is the proper procedure before performing maintenance on a gas
appliance?
A. Turn off the pilot only
B. Shut off the gas supply
C. Vent the room only
D. Disconnect electrical supply only
Rationale: Gas must be shut off to prevent leaks or explosions during
maintenance.
9. What is the minimum burial depth for underground gas piping in
Massachusetts?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Rationale: Underground gas piping must be buried at least 12 inches
below grade to prevent accidental damage.
10.When testing gas piping with air pressure, what is the maximum pressure
allowed?
A. 5 psi
B. 5 psi
C. 10 psi
D. 15 psi
Practice Test Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A Instant Download
1. What is the minimum distance a natural gas meter must be installed from
an ignition source in Massachusetts?
A. 6 inches
B. 12 inches
C. 18 inches
D. 12 inches
Rationale: Massachusetts code requires natural gas meters to be at least
12 inches from ignition sources to prevent fire hazards.
2. What is the primary purpose of a drip leg in a gas piping system?
A. To reduce pressure
B. To collect moisture and debris
C. To regulate gas flow
D. To vent excess gas
Rationale: A drip leg (sediment trap) collects moisture and debris to
protect downstream equipment from contamination.
3. What type of piping is typically prohibited for interior natural gas
distribution in Massachusetts?
, A. Black steel
B. CSST
C. PVC
D. Copper with approved fittings
Rationale: PVC is not permitted for interior natural gas distribution due to
fire and pressure hazards.
4. Which gas pressure is typically considered "low pressure" for residential
natural gas systems?
A. 1 psi
B. 0.5 psi or less
C. 2 psi
D. 5 psi
Rationale: Residential natural gas systems usually operate at low pressure
(0.5 psi or below).
5. What is the required minimum clearance for a gas appliance vent terminal
from a window or door?
A. 3 feet
B. 12 inches
C. 6 inches
D. 24 inches
Rationale: Massachusetts code requires vent terminals to be at least 12
inches from windows, doors, or openings to prevent backdrafting or
ignition of flammable vapors.
6. Which type of joint is preferred for black steel gas piping?
A. Compression
B. Soldered
C. Threaded
D. Flanged
Rationale: Threaded joints are standard for black steel piping because
they provide a strong, leak-resistant seal.
, 7. What is the maximum allowable pressure drop in a natural gas distribution
system from meter to appliance?
A. 0.5 psi
B. 0.5 inch WC
C. 1 psi
D. 1 inch WC
Rationale: Pressure drop should not exceed 0.5 inches water column for
safe and efficient appliance operation.
8. What is the proper procedure before performing maintenance on a gas
appliance?
A. Turn off the pilot only
B. Shut off the gas supply
C. Vent the room only
D. Disconnect electrical supply only
Rationale: Gas must be shut off to prevent leaks or explosions during
maintenance.
9. What is the minimum burial depth for underground gas piping in
Massachusetts?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Rationale: Underground gas piping must be buried at least 12 inches
below grade to prevent accidental damage.
10.When testing gas piping with air pressure, what is the maximum pressure
allowed?
A. 5 psi
B. 5 psi
C. 10 psi
D. 15 psi
