New Mexico (NM) JG Journeyman Natural
Gas Fitter Practice Exam | Questions and
Answers
Question 1: You are installing a new natural gas-fired storage water heater in a
residential garage in Albuquerque, NM. According to the International Fuel Gas
Code (IFGC), what specific elevation requirement must be met regarding the
ignition source of this appliance?
A) The ignition source must be at least 6 inches above the floor.
B) The ignition source must be at least 12 inches above the floor.
C) The ignition source must be at least 18 inches above the floor.
D) There is no elevation requirement if the water heater is FVIR (Flammable Vapor
Ignition Resistant) certified.
CORRECT ANSWER: C) The ignition source must be at least 18 inches above the
floor.
Rationale: IFGC Section 304.1 and the International Mechanical Code (IMC) require
that appliances with ignition sources installed in garages be elevated a minimum
of 18 inches above the finished floor to prevent the ignition of heavier-than-air
flammable vapors (like gasoline) that may settle on the garage floor. Even with
FVIR certification, local jurisdictions and the base code generally mandate this 18-
inch clearance for safety.
Question 2: A Journeyman Gas Fitter is sizing a gas piping system for a new
custom home in Santa Fe, NM (elevation 7,200 feet). When calculating the
required BTU input for the appliances to determine pipe sizing, what critical
adjustment must the fitter make to the appliance nameplate ratings?
A) Increase the BTU rating by 4% for every 1,000 feet above sea level.
B) Derate the appliance input rating by 4% for every 1,000 feet above 2,000 feet of
elevation.
C) Derate the BTU rating by 2% for every 1,000 feet above 4,500 feet.
D) No adjustment is necessary; pipe sizing is based on the sea-level nameplate
rating regardless of altitude.
CORRECT ANSWER: B) Derate the appliance input rating by 4% for every 1,000
feet above 2,000 feet of elevation.
Rationale: At high altitudes, the air is less dense, meaning less oxygen is available
for combustion. The IFGC and most appliance manufacturers require derating the
input BTUs (typically 4% per 1,000 feet above 2,000 feet) to ensure proper
Page 1 of 64
,combustion and prevent sooting or carbon monoxide production. Pipe sizing must
be based on this derated load, as the actual gas consumption will be lower.
Question 3: While installing Corrugated Stainless Steel Tubing (CSST) in a
residential retrofit, the homeowner asks why you are connecting a solid copper
grounding wire from the gas piping system to the home’s electrical grounding
electrode system. What code requirement are you fulfilling?
A) Preventing galvanic corrosion between the CSST and black iron pipe.
B) Bonding and grounding the CSST to prevent arc-over damage from lightning or
indirect electrical strikes.
C) Providing a path for static electricity generated by high-velocity gas flow.
D) Ensuring the gas meter registers accurate flow rates.
CORRECT ANSWER: B) Bonding and grounding the CSST to prevent arc-over
damage from lightning or indirect electrical strikes.
Rationale: NFPA 54 (National Fuel Gas Code) and CSST manufacturer instructions
strictly require that CSST systems be bonded to the electrical service grounding
electrode system. If a lightning strike or power surge hits the home, an
ungrounded CSST line can become energized; the resulting arc can puncture the
thin stainless steel inner liner, causing a catastrophic gas leak and fire.
Question 4: You are installing a commercial gas-fired range in a restaurant. The
manufacturer’s installation instructions do not specify a sediment trap (drip leg).
According to the IFGC, what is your required course of action?
A) Install a sediment trap anyway, as it is required by code for all appliances except
specific listed exceptions.
B) Do not install a sediment trap, as the manufacturer's instructions always
supersede the code.
C) Install a sediment trap only if the gas pressure exceeds 2 psig.
D) Install a union immediately upstream of the appliance shutoff valve in lieu of a
sediment trap.
CORRECT ANSWER: A) Install a sediment trap anyway, as it is required by code
for all appliances except specific listed exceptions.
Rationale: IFGC Section 408.4 requires a sediment trap to be installed upstream of
all appliances unless the appliance is specifically exempted (e.g., some commercial
cooking appliances where it would cause a hazard, or appliances with internal
protective screens). However, if the manufacturer explicitly states not to install one
because it voids the warranty or causes a hazard, you follow the manufacturer. If
they are simply silent on it, the code mandates its installation to catch pipe scale,
dirt, and moisture.
Question 5: A gas fitter is installing a new underground polyethylene (PE) gas
service line from the street main to a residential meter. According to NM
Page 2 of 64
,regulations and the IFGC, what is the minimum burial depth required for the PE
pipe in a private yard, and what additional safety measure must be installed?
A) 12 inches minimum depth with no additional requirements.
B) 18 inches minimum depth with a continuous warning tape installed 12 inches
above the pipe.
C) 24 inches minimum depth with a continuous warning tape installed 12 inches
above the pipe.
D) 18 inches minimum depth, but warning tape is only required in commercial
zones.
CORRECT ANSWER: B) 18 inches minimum depth with a continuous warning
tape installed 12 inches above the pipe.
Rationale: IFGC Section 405.3 and NM CID regulations dictate that underground
gas piping must be buried at a minimum depth of 18 inches in private property
(and 24 inches under public streets/sidewalks). A non-metallic, continuous warning
tape must be buried approximately 12 inches above the underground pipe to alert
future excavators of the gas line's presence.
Question 6: You are testing a newly installed residential natural gas piping
system that operates at a normal service pressure of 1/2 psig (14 inches w.c.).
What is the minimum test pressure and duration required by the IFGC to prove
the system is tight?
A) 10 psig for 15 minutes.
B) 15 psig for 10 minutes.
C) 1.5 times the operating pressure for 30 minutes.
D) 5 psig for 5 minutes.
CORRECT ANSWER: B) 15 psig for 10 minutes.
Rationale: IFGC Section 406.2 states that new piping must be tested with air or
inert gas. For systems operating at 1 psig or less (typical residential), the test
pressure must be at least 15 psig, and the test must last for a minimum of 10
minutes without a drop in pressure. (Note: If testing an existing system with the
appliance connected, the test pressure is limited to 10 psig or 1.5x operating
pressure, but for new piping, 15 psig for 10 mins is the standard).
Question 7: When installing a gas pressure regulator that has an atmospheric
vent, where must the vent be terminated to comply with the IFGC?
A) Terminated in the attic space, provided it is screened.
B) Terminated inside the mechanical closet, pointing downward.
C) Piped to the outdoors, with the termination point screened and located where it
will not be blocked by snow, ice, or debris.
D) Venting is not required if the regulator is equipped with a vent limiter.
CORRECT ANSWER: C) Piped to the outdoors, with the termination point
screened and located where it will not be blocked by snow, ice, or debris.
Page 3 of 64
, Rationale: IFGC Section 404.8 requires that regulator vents be piped to the
outdoors if the regulator is installed indoors. The vent must be screened (typically
1/4 inch mesh) to prevent insect/rodent entry and located where it won't be
blocked by snow (a critical consideration in NM winters) or ice, which could cause
the regulator to fail and over-pressurize the downstream piping.
Question 8: A homeowner wants to install a decorative, unvented gas log set in
their tightly sealed, modern bedroom. According to the IFGC and NM
regulations, what is the maximum BTU input allowed for an unvented gas
appliance in a bedroom?
A) 10,000 BTUs per hour.
B) 6,000 BTUs per hour.
C) Unvented gas appliances are strictly prohibited in bedrooms and bathrooms.
D) 20,000 BTUs per hour, provided an ODS (Oxygen Depletion Sensor) is installed.
CORRECT ANSWER: C) Unvented gas appliances are strictly prohibited in
bedrooms and bathrooms.
Rationale: IFGC Section 303.6 and general NM mechanical codes prohibit
unvented combustion appliances (like unvented gas logs) from being installed in
bedrooms, bathrooms, or sleeping rooms due to the severe risk of carbon
monoxide poisoning and oxygen depletion in confined, occupied spaces where
people sleep.
Question 9: You are installing a Category IV high-efficiency gas furnace that
vents using PVC pipe. The manufacturer specifies a maximum vent length of 60
feet. What specific slope requirement must be maintained on the vent piping,
and why?
A) Slope upward 1/4 inch per foot toward the furnace to prevent rain entry.
B) Slope downward 1/4 inch per foot back to the furnace to allow condensate
drainage.
C) Vent piping must be perfectly level to prevent condensate pooling.
D) Slope downward 1/2 inch per foot toward the exterior termination.
CORRECT ANSWER: B) Slope downward 1/4 inch per foot back to the furnace to
allow condensate drainage.
Rationale: Category IV appliances operate with positive vent pressure and produce
highly acidic liquid condensate. The IFGC and manufacturer instructions require
the vent piping to slope downward toward the appliance (or toward a dedicated
condensate trap) at a minimum of 1/4 inch per foot so the condensate drains back
into the furnace's internal condensate collection box and out to a drain,
preventing pooling and freezing in the vent.
Question 10: In a commercial kitchen, you are installing a gas-fired fryer. The
appliance shutoff valve must be located within what maximum distance from
Page 4 of 64
Gas Fitter Practice Exam | Questions and
Answers
Question 1: You are installing a new natural gas-fired storage water heater in a
residential garage in Albuquerque, NM. According to the International Fuel Gas
Code (IFGC), what specific elevation requirement must be met regarding the
ignition source of this appliance?
A) The ignition source must be at least 6 inches above the floor.
B) The ignition source must be at least 12 inches above the floor.
C) The ignition source must be at least 18 inches above the floor.
D) There is no elevation requirement if the water heater is FVIR (Flammable Vapor
Ignition Resistant) certified.
CORRECT ANSWER: C) The ignition source must be at least 18 inches above the
floor.
Rationale: IFGC Section 304.1 and the International Mechanical Code (IMC) require
that appliances with ignition sources installed in garages be elevated a minimum
of 18 inches above the finished floor to prevent the ignition of heavier-than-air
flammable vapors (like gasoline) that may settle on the garage floor. Even with
FVIR certification, local jurisdictions and the base code generally mandate this 18-
inch clearance for safety.
Question 2: A Journeyman Gas Fitter is sizing a gas piping system for a new
custom home in Santa Fe, NM (elevation 7,200 feet). When calculating the
required BTU input for the appliances to determine pipe sizing, what critical
adjustment must the fitter make to the appliance nameplate ratings?
A) Increase the BTU rating by 4% for every 1,000 feet above sea level.
B) Derate the appliance input rating by 4% for every 1,000 feet above 2,000 feet of
elevation.
C) Derate the BTU rating by 2% for every 1,000 feet above 4,500 feet.
D) No adjustment is necessary; pipe sizing is based on the sea-level nameplate
rating regardless of altitude.
CORRECT ANSWER: B) Derate the appliance input rating by 4% for every 1,000
feet above 2,000 feet of elevation.
Rationale: At high altitudes, the air is less dense, meaning less oxygen is available
for combustion. The IFGC and most appliance manufacturers require derating the
input BTUs (typically 4% per 1,000 feet above 2,000 feet) to ensure proper
Page 1 of 64
,combustion and prevent sooting or carbon monoxide production. Pipe sizing must
be based on this derated load, as the actual gas consumption will be lower.
Question 3: While installing Corrugated Stainless Steel Tubing (CSST) in a
residential retrofit, the homeowner asks why you are connecting a solid copper
grounding wire from the gas piping system to the home’s electrical grounding
electrode system. What code requirement are you fulfilling?
A) Preventing galvanic corrosion between the CSST and black iron pipe.
B) Bonding and grounding the CSST to prevent arc-over damage from lightning or
indirect electrical strikes.
C) Providing a path for static electricity generated by high-velocity gas flow.
D) Ensuring the gas meter registers accurate flow rates.
CORRECT ANSWER: B) Bonding and grounding the CSST to prevent arc-over
damage from lightning or indirect electrical strikes.
Rationale: NFPA 54 (National Fuel Gas Code) and CSST manufacturer instructions
strictly require that CSST systems be bonded to the electrical service grounding
electrode system. If a lightning strike or power surge hits the home, an
ungrounded CSST line can become energized; the resulting arc can puncture the
thin stainless steel inner liner, causing a catastrophic gas leak and fire.
Question 4: You are installing a commercial gas-fired range in a restaurant. The
manufacturer’s installation instructions do not specify a sediment trap (drip leg).
According to the IFGC, what is your required course of action?
A) Install a sediment trap anyway, as it is required by code for all appliances except
specific listed exceptions.
B) Do not install a sediment trap, as the manufacturer's instructions always
supersede the code.
C) Install a sediment trap only if the gas pressure exceeds 2 psig.
D) Install a union immediately upstream of the appliance shutoff valve in lieu of a
sediment trap.
CORRECT ANSWER: A) Install a sediment trap anyway, as it is required by code
for all appliances except specific listed exceptions.
Rationale: IFGC Section 408.4 requires a sediment trap to be installed upstream of
all appliances unless the appliance is specifically exempted (e.g., some commercial
cooking appliances where it would cause a hazard, or appliances with internal
protective screens). However, if the manufacturer explicitly states not to install one
because it voids the warranty or causes a hazard, you follow the manufacturer. If
they are simply silent on it, the code mandates its installation to catch pipe scale,
dirt, and moisture.
Question 5: A gas fitter is installing a new underground polyethylene (PE) gas
service line from the street main to a residential meter. According to NM
Page 2 of 64
,regulations and the IFGC, what is the minimum burial depth required for the PE
pipe in a private yard, and what additional safety measure must be installed?
A) 12 inches minimum depth with no additional requirements.
B) 18 inches minimum depth with a continuous warning tape installed 12 inches
above the pipe.
C) 24 inches minimum depth with a continuous warning tape installed 12 inches
above the pipe.
D) 18 inches minimum depth, but warning tape is only required in commercial
zones.
CORRECT ANSWER: B) 18 inches minimum depth with a continuous warning
tape installed 12 inches above the pipe.
Rationale: IFGC Section 405.3 and NM CID regulations dictate that underground
gas piping must be buried at a minimum depth of 18 inches in private property
(and 24 inches under public streets/sidewalks). A non-metallic, continuous warning
tape must be buried approximately 12 inches above the underground pipe to alert
future excavators of the gas line's presence.
Question 6: You are testing a newly installed residential natural gas piping
system that operates at a normal service pressure of 1/2 psig (14 inches w.c.).
What is the minimum test pressure and duration required by the IFGC to prove
the system is tight?
A) 10 psig for 15 minutes.
B) 15 psig for 10 minutes.
C) 1.5 times the operating pressure for 30 minutes.
D) 5 psig for 5 minutes.
CORRECT ANSWER: B) 15 psig for 10 minutes.
Rationale: IFGC Section 406.2 states that new piping must be tested with air or
inert gas. For systems operating at 1 psig or less (typical residential), the test
pressure must be at least 15 psig, and the test must last for a minimum of 10
minutes without a drop in pressure. (Note: If testing an existing system with the
appliance connected, the test pressure is limited to 10 psig or 1.5x operating
pressure, but for new piping, 15 psig for 10 mins is the standard).
Question 7: When installing a gas pressure regulator that has an atmospheric
vent, where must the vent be terminated to comply with the IFGC?
A) Terminated in the attic space, provided it is screened.
B) Terminated inside the mechanical closet, pointing downward.
C) Piped to the outdoors, with the termination point screened and located where it
will not be blocked by snow, ice, or debris.
D) Venting is not required if the regulator is equipped with a vent limiter.
CORRECT ANSWER: C) Piped to the outdoors, with the termination point
screened and located where it will not be blocked by snow, ice, or debris.
Page 3 of 64
, Rationale: IFGC Section 404.8 requires that regulator vents be piped to the
outdoors if the regulator is installed indoors. The vent must be screened (typically
1/4 inch mesh) to prevent insect/rodent entry and located where it won't be
blocked by snow (a critical consideration in NM winters) or ice, which could cause
the regulator to fail and over-pressurize the downstream piping.
Question 8: A homeowner wants to install a decorative, unvented gas log set in
their tightly sealed, modern bedroom. According to the IFGC and NM
regulations, what is the maximum BTU input allowed for an unvented gas
appliance in a bedroom?
A) 10,000 BTUs per hour.
B) 6,000 BTUs per hour.
C) Unvented gas appliances are strictly prohibited in bedrooms and bathrooms.
D) 20,000 BTUs per hour, provided an ODS (Oxygen Depletion Sensor) is installed.
CORRECT ANSWER: C) Unvented gas appliances are strictly prohibited in
bedrooms and bathrooms.
Rationale: IFGC Section 303.6 and general NM mechanical codes prohibit
unvented combustion appliances (like unvented gas logs) from being installed in
bedrooms, bathrooms, or sleeping rooms due to the severe risk of carbon
monoxide poisoning and oxygen depletion in confined, occupied spaces where
people sleep.
Question 9: You are installing a Category IV high-efficiency gas furnace that
vents using PVC pipe. The manufacturer specifies a maximum vent length of 60
feet. What specific slope requirement must be maintained on the vent piping,
and why?
A) Slope upward 1/4 inch per foot toward the furnace to prevent rain entry.
B) Slope downward 1/4 inch per foot back to the furnace to allow condensate
drainage.
C) Vent piping must be perfectly level to prevent condensate pooling.
D) Slope downward 1/2 inch per foot toward the exterior termination.
CORRECT ANSWER: B) Slope downward 1/4 inch per foot back to the furnace to
allow condensate drainage.
Rationale: Category IV appliances operate with positive vent pressure and produce
highly acidic liquid condensate. The IFGC and manufacturer instructions require
the vent piping to slope downward toward the appliance (or toward a dedicated
condensate trap) at a minimum of 1/4 inch per foot so the condensate drains back
into the furnace's internal condensate collection box and out to a drain,
preventing pooling and freezing in the vent.
Question 10: In a commercial kitchen, you are installing a gas-fired fryer. The
appliance shutoff valve must be located within what maximum distance from
Page 4 of 64
