Gas Piping Systems Certification
Exam (2026 Edition)||| questions and
answers with rationales/graded
A+/2026 update/100% correct
/instant download
Exam Code: GPS-2026-CERT
Total Questions: 85
Passing Score: 75% (64 correct)
Time Allowed: 120 minutes
Instructions: Select the best answer for each question. Correct answers
are highlighted in bold.
Part 1: Safety & Code Compliance (Questions 1–15)
1. The primary code governing gas piping systems in most U.S. jurisdictions
(2026 edition) is:
a) ASME B31.3
b) NFPA 54 / ANSI Z223.1
c) API 1104
d) ASHRAE 15
Rationale: NFPA 54 (National Fuel Gas Code) is the standard for gas piping,
updated for 2026 with new leak detection requirements.
2. A gas piping system must be tested for leaks using:
a) Oxygen at 100 psi
b) Air or inert gas at 1.5 times working pressure (min 3 psi for 10 min)
c) Acetylene flame
d) Water at 200 psi
Rationale: NFPA 54 2026 requires air/inert gas (never oxygen) at 1.5x SWP, ≥3
psi, pressure held for 10 min.
,3. In a multi-family building, the main gas shut-off valve must be located:
a) Inside each apartment near fireplace
b) At the point of entry to the building, exterior accessible
c) Inside boiler room only
d) On rooftop
Rationale: 2026 code mandates exterior building entry shut-off for emergency
response.
4. Excess flow valves (EFVs) are required for new or replaced service lines
serving:
a) Any appliance under 10,000 Btu/hr
b) Single-family homes with 1-3 psi systems (effective 2026)
c) Industrial boilers only
d) Outdoor grills
Rationale: 2026 update extends EFVs to all new SFH services ≤10 psi.
5. Which material is NOT permitted for natural gas piping indoors?
a) Black steel schedule 40
b) Corrugated stainless steel tubing (CSST)
c) Galvanized steel (unless approved)
d) Polyethylene (PE)
Rationale: PE is only for underground; galvanized coating can flake and clog
orifices.
6. The maximum allowable pressure drop from meter to farthest appliance is
typically:
a) 2 psi
b) 0.5 inches w.c. (for low-pressure systems)
c) 10 inches w.c.
d) 5 psi
Rationale: Low-pressure systems (7-14” w.c.) ≤0.5” w.c. drop.
7. A sediment trap (drip leg) is required:
a) At every 90° elbow
b) Before each appliance gas valve
c) At meter outlet only
d) Only for propane systems
Rationale: Catches debris/condensate to protect appliance valve.
, 8. In a confined space (>50 ft of piping), ventilation is required when working
because:
a) Gas is heavier than air and displaces oxygen
b) To prevent build-up of methane or carbon monoxide
c) Piping may overheat
d) Required by OSHA 1926.353
Rationale: Gas leaks can displace oxygen; ventilation is mandatory.
9. The 2026 code adds mandatory bonding for CSST to:
a) Water pipe
b) Building grounding electrode system
c) Gas meter case
d) Neutral bus
Rationale: Lightning protection – CSST must be bonded directly to grounding
electrode.
10. Which appliance requires a manual shut-off valve within 6 feet?
a) Furnace only
b) All gas appliances
c) Water heater only
d) Cooktop only
Rationale: NFPA 54: dedicated shut-off within 6’ or same room.
11. Propane (LPG) piping systems must use:
a) Same sizing tables as natural gas
b) Higher pressure rating because propane is heavier
c) Copper tubing always
d) Plastic underground only
Rationale: Propane has higher vapor density and pressure; piping sized
specifically for propane tables.
12. A gas pressure regulator must have a vent that:
a) Is capped to prevent debris
b) Terminates outdoors (or to safe area)
c) Faces upward
d) Is at least 10 ft from building
Rationale: Prevents gas accumulation indoors if regulator fails.
13. During a pressure test, the gauge accuracy must be:
a) ±5%
Exam (2026 Edition)||| questions and
answers with rationales/graded
A+/2026 update/100% correct
/instant download
Exam Code: GPS-2026-CERT
Total Questions: 85
Passing Score: 75% (64 correct)
Time Allowed: 120 minutes
Instructions: Select the best answer for each question. Correct answers
are highlighted in bold.
Part 1: Safety & Code Compliance (Questions 1–15)
1. The primary code governing gas piping systems in most U.S. jurisdictions
(2026 edition) is:
a) ASME B31.3
b) NFPA 54 / ANSI Z223.1
c) API 1104
d) ASHRAE 15
Rationale: NFPA 54 (National Fuel Gas Code) is the standard for gas piping,
updated for 2026 with new leak detection requirements.
2. A gas piping system must be tested for leaks using:
a) Oxygen at 100 psi
b) Air or inert gas at 1.5 times working pressure (min 3 psi for 10 min)
c) Acetylene flame
d) Water at 200 psi
Rationale: NFPA 54 2026 requires air/inert gas (never oxygen) at 1.5x SWP, ≥3
psi, pressure held for 10 min.
,3. In a multi-family building, the main gas shut-off valve must be located:
a) Inside each apartment near fireplace
b) At the point of entry to the building, exterior accessible
c) Inside boiler room only
d) On rooftop
Rationale: 2026 code mandates exterior building entry shut-off for emergency
response.
4. Excess flow valves (EFVs) are required for new or replaced service lines
serving:
a) Any appliance under 10,000 Btu/hr
b) Single-family homes with 1-3 psi systems (effective 2026)
c) Industrial boilers only
d) Outdoor grills
Rationale: 2026 update extends EFVs to all new SFH services ≤10 psi.
5. Which material is NOT permitted for natural gas piping indoors?
a) Black steel schedule 40
b) Corrugated stainless steel tubing (CSST)
c) Galvanized steel (unless approved)
d) Polyethylene (PE)
Rationale: PE is only for underground; galvanized coating can flake and clog
orifices.
6. The maximum allowable pressure drop from meter to farthest appliance is
typically:
a) 2 psi
b) 0.5 inches w.c. (for low-pressure systems)
c) 10 inches w.c.
d) 5 psi
Rationale: Low-pressure systems (7-14” w.c.) ≤0.5” w.c. drop.
7. A sediment trap (drip leg) is required:
a) At every 90° elbow
b) Before each appliance gas valve
c) At meter outlet only
d) Only for propane systems
Rationale: Catches debris/condensate to protect appliance valve.
, 8. In a confined space (>50 ft of piping), ventilation is required when working
because:
a) Gas is heavier than air and displaces oxygen
b) To prevent build-up of methane or carbon monoxide
c) Piping may overheat
d) Required by OSHA 1926.353
Rationale: Gas leaks can displace oxygen; ventilation is mandatory.
9. The 2026 code adds mandatory bonding for CSST to:
a) Water pipe
b) Building grounding electrode system
c) Gas meter case
d) Neutral bus
Rationale: Lightning protection – CSST must be bonded directly to grounding
electrode.
10. Which appliance requires a manual shut-off valve within 6 feet?
a) Furnace only
b) All gas appliances
c) Water heater only
d) Cooktop only
Rationale: NFPA 54: dedicated shut-off within 6’ or same room.
11. Propane (LPG) piping systems must use:
a) Same sizing tables as natural gas
b) Higher pressure rating because propane is heavier
c) Copper tubing always
d) Plastic underground only
Rationale: Propane has higher vapor density and pressure; piping sized
specifically for propane tables.
12. A gas pressure regulator must have a vent that:
a) Is capped to prevent debris
b) Terminates outdoors (or to safe area)
c) Faces upward
d) Is at least 10 ft from building
Rationale: Prevents gas accumulation indoors if regulator fails.
13. During a pressure test, the gauge accuracy must be:
a) ±5%
