NEW MEXICO JG JOURNEYMAN NATURAL GAS FITTER
COMPLETE EXAM QUESTIONS AND VERIFIED ANSWERS |
2026–2027 LATEST UPDATE | GUARANTEED PASS | DETAILED
RATIONALES | FULL STUDY GUIDE | EXAM PREP | PRACTICE
TEST | CERTIFICATION PREPARATION
SECTION ONE — QUESTIONS 1–100
1. A Journeyman Natural Gas Fitter in New Mexico is installing a gas piping system operating at 5
psi inside a commercial kitchen. This installation must comply primarily with which code?
A) International Fuel Gas Code (IFGC) as adopted by New Mexico with state amendments
B) International Residential Code (IRC) only
C) Uniform Plumbing Code (UPC) without amendments
D) National Fuel Gas Code (NFPA 54) without local amendments
Correct Answer: A) International Fuel Gas Code (IFGC) as adopted by New Mexico with state
amendments
Rationale: New Mexico adopts the International Fuel Gas Code (IFGC) with state-specific amendments
for commercial and residential gas fitting work. The IRC applies only to residential construction, while
the UPC is not the primary gas code in New Mexico. NFPA 54 is largely harmonized with IFGC, but the
state specifically adopts IFGC as its base code with amendments .
2. What is the minimum test pressure required for a new polyethylene (PE) plastic gas service line
operating below 10 psi when testing for leakage from the main to the meter set?
A) 3 psi for 15 minutes
B) 10 psi for 30 minutes
C) 60 psi for 30 minutes
D) 100 psi for 60 minutes
Correct Answer: C) 60 psi for 30 minutes
Rationale: For plastic pipe (typically polyethylene) used in natural gas distribution, the code requires a
pressure test of at least 60 psi for a minimum of 30 minutes with no pressure drop observed. Lower
pressures are insufficient for detecting leaks in plastic joints, while 100 psi is typically required for
higher-pressure systems or specific conditions .
3. What is the maximum allowable length for a flexible appliance connector used with a movable
appliance such as a commercial range in New Mexico?
A) 3 feet
B) 4 feet
C) 6 feet
D) 8 feet
Correct Answer: C) 6 feet
,Rationale: The IFGC and New Mexico amendments limit an appliance connector for a movable
appliance to 6 feet in length. For stationary appliances, shorter lengths (typically 3 feet) are common,
but movable appliances may use up to 6 feet. Lengths exceeding this require rigid piping
installations .
4. What is the minimum burial depth required for a polyethylene (PE) natural gas pipe installed
under a residential driveway in New Mexico when not subject to heavy truck loading?
A) 12 inches
B) 18 inches
C) 24 inches
D) 30 inches
Correct Answer: B) 18 inches
Rationale: Under residential driveways and parking areas, the minimum cover for PE gas pipe is 18
inches. In non-trafficked areas, the minimum cover is 12 inches. Under roads or areas subject to
heavy truck loading, the burial depth increases to 24 to 30 inches .
5. A gas fitter installs a gas line inside a concealed wall cavity. Which method is acceptable for
protecting the line from physical damage?
A) Wrapping the pipe with electrical tape
B) Installing a 16-gauge steel protective plate over the pipe
C) Using Schedule 10 black iron pipe without additional protection
D) Burying the pipe in spray foam insulation
Correct Answer: B) Installing a 16-gauge steel protective plate over the pipe
Rationale: Concealed gas piping requires protection from nails or screws that could penetrate the
pipe. A steel plate at least 1/16 inch thick (16 gauge) is an accepted protection method. Schedule 10
pipe is too thin for this application, and electrical tape and spray foam provide no mechanical
protection .
6. When using a manometer to measure gas pressure at an appliance's manifold, what is the
correct procedure?
A) Adjust the appliance's pressure regulator to 4.0 inches WC to compensate for elevation in New
Mexico
B) Read pressure with appliance off and main gas cock open
C) Measure with the appliance running and all other gas appliances in the building at maximum
demand
D) Measure with the appliance off and all other appliances off
Correct Answer: C) Measure with the appliance running and all other gas appliances in the building
at maximum demand
Rationale: Manifold pressure must be checked with the appliance operating at full fire and all other
gas appliances on the system operating simultaneously. This ensures proper supply under maximum
load conditions and verifies that the regulator can maintain rated pressure under peak demand .
7. What is the primary purpose of adding odorants such as mercaptan to natural gas?
, A) To improve combustion efficiency
B) To facilitate leak detection
C) To increase the energy content of the gas
D) To reduce the flammability of the gas
Correct Answer: B) To facilitate leak detection
Rationale: Odorants like mercaptan are added to natural gas to give it a distinctive, unpleasant smell,
making gas leaks detectable by human senses. Natural gas in its pure state is colorless and odorless,
making leaks impossible to detect without odorization. This safety measure is required by all major
gas codes .
8. Which material is PROHIBITED for use as interior natural gas piping in New Mexico?
A) Black iron pipe
B) Type L copper
C) Corrugated Stainless Steel Tubing (CSST)
D) Polyvinyl Chloride (PVC) pipe
Correct Answer: D) Polyvinyl Chloride (PVC) pipe
Rationale: PVC pipe is not approved for use in gas conveyance systems. While approved for certain
water applications, it is not rated for gas pressure or potential temperature extremes and is
prohibited by all relevant gas codes. Approved materials include black iron, copper, and CSST .
9. What is the specific gravity of natural gas compared to air?
A) Approximately 0.65
B) Approximately 1.0
C) Approximately 1.5
D) Approximately 2.0
Correct Answer: A) Approximately 0.65
Rationale: Natural gas typically has a specific gravity of about 0.65 relative to air (where air = 1.0).
This means natural gas is lighter than air and will rise and dissipate upward if released, unlike
propane which has a specific gravity of approximately 1.5 and is heavier than air .
10. What combustion byproduct is considered a major health hazard if not properly vented from a
gas appliance?
A) Carbon dioxide
B) Carbon monoxide
C) Nitrogen
D) Water vapor
Correct Answer: B) Carbon monoxide
Rationale: Carbon monoxide is a poisonous, colorless, odorless gas produced during incomplete
combustion of natural gas. Proper venting is essential for safety, as carbon monoxide exposure can
cause serious health effects including asphyxiation. All gas appliances must be properly vented to
exhaust this dangerous byproduct .
COMPLETE EXAM QUESTIONS AND VERIFIED ANSWERS |
2026–2027 LATEST UPDATE | GUARANTEED PASS | DETAILED
RATIONALES | FULL STUDY GUIDE | EXAM PREP | PRACTICE
TEST | CERTIFICATION PREPARATION
SECTION ONE — QUESTIONS 1–100
1. A Journeyman Natural Gas Fitter in New Mexico is installing a gas piping system operating at 5
psi inside a commercial kitchen. This installation must comply primarily with which code?
A) International Fuel Gas Code (IFGC) as adopted by New Mexico with state amendments
B) International Residential Code (IRC) only
C) Uniform Plumbing Code (UPC) without amendments
D) National Fuel Gas Code (NFPA 54) without local amendments
Correct Answer: A) International Fuel Gas Code (IFGC) as adopted by New Mexico with state
amendments
Rationale: New Mexico adopts the International Fuel Gas Code (IFGC) with state-specific amendments
for commercial and residential gas fitting work. The IRC applies only to residential construction, while
the UPC is not the primary gas code in New Mexico. NFPA 54 is largely harmonized with IFGC, but the
state specifically adopts IFGC as its base code with amendments .
2. What is the minimum test pressure required for a new polyethylene (PE) plastic gas service line
operating below 10 psi when testing for leakage from the main to the meter set?
A) 3 psi for 15 minutes
B) 10 psi for 30 minutes
C) 60 psi for 30 minutes
D) 100 psi for 60 minutes
Correct Answer: C) 60 psi for 30 minutes
Rationale: For plastic pipe (typically polyethylene) used in natural gas distribution, the code requires a
pressure test of at least 60 psi for a minimum of 30 minutes with no pressure drop observed. Lower
pressures are insufficient for detecting leaks in plastic joints, while 100 psi is typically required for
higher-pressure systems or specific conditions .
3. What is the maximum allowable length for a flexible appliance connector used with a movable
appliance such as a commercial range in New Mexico?
A) 3 feet
B) 4 feet
C) 6 feet
D) 8 feet
Correct Answer: C) 6 feet
,Rationale: The IFGC and New Mexico amendments limit an appliance connector for a movable
appliance to 6 feet in length. For stationary appliances, shorter lengths (typically 3 feet) are common,
but movable appliances may use up to 6 feet. Lengths exceeding this require rigid piping
installations .
4. What is the minimum burial depth required for a polyethylene (PE) natural gas pipe installed
under a residential driveway in New Mexico when not subject to heavy truck loading?
A) 12 inches
B) 18 inches
C) 24 inches
D) 30 inches
Correct Answer: B) 18 inches
Rationale: Under residential driveways and parking areas, the minimum cover for PE gas pipe is 18
inches. In non-trafficked areas, the minimum cover is 12 inches. Under roads or areas subject to
heavy truck loading, the burial depth increases to 24 to 30 inches .
5. A gas fitter installs a gas line inside a concealed wall cavity. Which method is acceptable for
protecting the line from physical damage?
A) Wrapping the pipe with electrical tape
B) Installing a 16-gauge steel protective plate over the pipe
C) Using Schedule 10 black iron pipe without additional protection
D) Burying the pipe in spray foam insulation
Correct Answer: B) Installing a 16-gauge steel protective plate over the pipe
Rationale: Concealed gas piping requires protection from nails or screws that could penetrate the
pipe. A steel plate at least 1/16 inch thick (16 gauge) is an accepted protection method. Schedule 10
pipe is too thin for this application, and electrical tape and spray foam provide no mechanical
protection .
6. When using a manometer to measure gas pressure at an appliance's manifold, what is the
correct procedure?
A) Adjust the appliance's pressure regulator to 4.0 inches WC to compensate for elevation in New
Mexico
B) Read pressure with appliance off and main gas cock open
C) Measure with the appliance running and all other gas appliances in the building at maximum
demand
D) Measure with the appliance off and all other appliances off
Correct Answer: C) Measure with the appliance running and all other gas appliances in the building
at maximum demand
Rationale: Manifold pressure must be checked with the appliance operating at full fire and all other
gas appliances on the system operating simultaneously. This ensures proper supply under maximum
load conditions and verifies that the regulator can maintain rated pressure under peak demand .
7. What is the primary purpose of adding odorants such as mercaptan to natural gas?
, A) To improve combustion efficiency
B) To facilitate leak detection
C) To increase the energy content of the gas
D) To reduce the flammability of the gas
Correct Answer: B) To facilitate leak detection
Rationale: Odorants like mercaptan are added to natural gas to give it a distinctive, unpleasant smell,
making gas leaks detectable by human senses. Natural gas in its pure state is colorless and odorless,
making leaks impossible to detect without odorization. This safety measure is required by all major
gas codes .
8. Which material is PROHIBITED for use as interior natural gas piping in New Mexico?
A) Black iron pipe
B) Type L copper
C) Corrugated Stainless Steel Tubing (CSST)
D) Polyvinyl Chloride (PVC) pipe
Correct Answer: D) Polyvinyl Chloride (PVC) pipe
Rationale: PVC pipe is not approved for use in gas conveyance systems. While approved for certain
water applications, it is not rated for gas pressure or potential temperature extremes and is
prohibited by all relevant gas codes. Approved materials include black iron, copper, and CSST .
9. What is the specific gravity of natural gas compared to air?
A) Approximately 0.65
B) Approximately 1.0
C) Approximately 1.5
D) Approximately 2.0
Correct Answer: A) Approximately 0.65
Rationale: Natural gas typically has a specific gravity of about 0.65 relative to air (where air = 1.0).
This means natural gas is lighter than air and will rise and dissipate upward if released, unlike
propane which has a specific gravity of approximately 1.5 and is heavier than air .
10. What combustion byproduct is considered a major health hazard if not properly vented from a
gas appliance?
A) Carbon dioxide
B) Carbon monoxide
C) Nitrogen
D) Water vapor
Correct Answer: B) Carbon monoxide
Rationale: Carbon monoxide is a poisonous, colorless, odorless gas produced during incomplete
combustion of natural gas. Proper venting is essential for safety, as carbon monoxide exposure can
cause serious health effects including asphyxiation. All gas appliances must be properly vented to
exhaust this dangerous byproduct .
