MCC-NH Gas Fitters Exam Questions with Answers
Verified by Experts
Please list the 4 most common inert gasses. ⬛
✓Correct Ans-Air, Nitrogen, Argon, Carbon Dioxide
During pressure tests what shall be left exposed for examination? If piping is concealed or
covered how do we examine the components that are required to be left exposed? ⬛ ✓Correct
Ans-
How do we isolate appliances and equipment not intended to be included in the pressure test?
✓Correct Ans-Disconnecting them and capping the outlets
⬛
How do we isolate appliances and equipment that are designed for pressures as high as those
used in the pressure test? ⬛
✓Correct Ans-By closing the appliance shut-off
How do we isolate appliances and equipment that are not designed for pressures as high as
those used in the pressure test? ⬛
✓Correct Ans-By closing the shut-offs and splitting the unions
If a mechanical gauge is used with the pressure test scale is allowed to be? ⬛
✓Correct Ans-up to
5 times the test pressure
What is the required test pressure? ⬛
✓Correct Ans-a minimum of 3 PSIg
How long should a pressure test last for piping with a volume greater than 10 cu ft.? ⬛
✓Correct
Ans-1/2 hour per 500 cubic feet up to a maximum 24 hours.
How long should a pressure test last for piping with a volume less than 10 cu ft.? ⬛
✓Correct
Ans-10 minutes minimum, 24 hours maximum
,Do we ever need to determine the volume of a residential piping system to figure out how long
the test duration needs to be? Why or why not? ⬛
✓Correct Ans-No, all residential installations
have a minimum of 10 minutes, and a maximum of 24 hours
How much is the pressure allowed to drop on a gas piping system when the pressure drop
cannot be attributed to a change in temperature? ⬛ ✓Correct Ans-0 PSIg (No change in pressure
that is not attributed to a change in temperature is allowed)
What is the maximum test duration regardless of volume? ⬛
✓Correct Ans-24 Hours
Where in the codebook can I find the formula to figure out how much the pressure is allowed to
change due to a change in temperature? ⬛✓Correct Ans-Annex B 7.5
If the pressure rises in a gas piping system are we required to use the formula to prove to the
inspector that the system does not have a leak and is gastight? Why or why not? ⬛ ✓Correct
Ans-If the AHJ wants it. They most likely will not.
If the pressure test indicates a leak how should the leak be located? What shall not be used?
✓Correct Ans-Bubble solution should be used, a lighter should not be used
⬛
What do we do when we find a leak? ⬛
✓Correct Ans-Turn off the gas, fix the leak, retest
List 5 reasons why a leak check should be performed. ⬛
✓Correct Ans-
What is the difference between when a pressure test and a leak test should be performed?
✓Correct Ans-leak tests are pressurized with the fuel gas, the pressure test is pressurized with
⬛
an inert gas.
What is the test medium and pressure used in a leak check? ⬛
✓Correct Ans-combustable gas
, What must we do when turning the gas on? ⬛
✓Correct Ans-Perform a leak check
What size piping may require the codebooks process of purging gas piping with inert gas before
being placed into service? ⬛
✓Correct Ans-It can't contain anything listed in table 8.3.1
What size piping may require the codebooks process of purging gas piping with inert gas when
being altered ⬛
✓Correct Ans-Anything listed in table 8.3.1
Explain what should happen with the discharge of purged gases? ⬛ ✓Correct Ans-It should be
purged indoors (if allowed), or outdoors (reference for outdoor purging requirements 8.3.1.3)
What is the minimum percentage needed to pass a written test for each specialty license?
✓Correct Ans-70%
⬛
What is the first tier to the specialty license? ⬛
✓Correct Ans-Gas Piping Installer
How many hours of educational training are required for the first specialty license? ⬛
✓Correct
Ans-60 Hours (Safemec 305.02)
How many hours of on-job-training are required for the first specialty license? ⬛
✓Correct Ans-
1000 Hours (Safemec 305.02)
What is the second tier to the specialty license? ⬛
✓Correct Ans-Fuel Gas Installation Technician
How many hours of educational training are required for the second specialty license?
✓Correct Ans-100 Hours Total (Safemec 305.03)
⬛
How many hours of on-job-training are required for the second specialty license? ⬛
✓Correct
Ans-1000 On Job Training Hours (Safemec 305.03)
Verified by Experts
Please list the 4 most common inert gasses. ⬛
✓Correct Ans-Air, Nitrogen, Argon, Carbon Dioxide
During pressure tests what shall be left exposed for examination? If piping is concealed or
covered how do we examine the components that are required to be left exposed? ⬛ ✓Correct
Ans-
How do we isolate appliances and equipment not intended to be included in the pressure test?
✓Correct Ans-Disconnecting them and capping the outlets
⬛
How do we isolate appliances and equipment that are designed for pressures as high as those
used in the pressure test? ⬛
✓Correct Ans-By closing the appliance shut-off
How do we isolate appliances and equipment that are not designed for pressures as high as
those used in the pressure test? ⬛
✓Correct Ans-By closing the shut-offs and splitting the unions
If a mechanical gauge is used with the pressure test scale is allowed to be? ⬛
✓Correct Ans-up to
5 times the test pressure
What is the required test pressure? ⬛
✓Correct Ans-a minimum of 3 PSIg
How long should a pressure test last for piping with a volume greater than 10 cu ft.? ⬛
✓Correct
Ans-1/2 hour per 500 cubic feet up to a maximum 24 hours.
How long should a pressure test last for piping with a volume less than 10 cu ft.? ⬛
✓Correct
Ans-10 minutes minimum, 24 hours maximum
,Do we ever need to determine the volume of a residential piping system to figure out how long
the test duration needs to be? Why or why not? ⬛
✓Correct Ans-No, all residential installations
have a minimum of 10 minutes, and a maximum of 24 hours
How much is the pressure allowed to drop on a gas piping system when the pressure drop
cannot be attributed to a change in temperature? ⬛ ✓Correct Ans-0 PSIg (No change in pressure
that is not attributed to a change in temperature is allowed)
What is the maximum test duration regardless of volume? ⬛
✓Correct Ans-24 Hours
Where in the codebook can I find the formula to figure out how much the pressure is allowed to
change due to a change in temperature? ⬛✓Correct Ans-Annex B 7.5
If the pressure rises in a gas piping system are we required to use the formula to prove to the
inspector that the system does not have a leak and is gastight? Why or why not? ⬛ ✓Correct
Ans-If the AHJ wants it. They most likely will not.
If the pressure test indicates a leak how should the leak be located? What shall not be used?
✓Correct Ans-Bubble solution should be used, a lighter should not be used
⬛
What do we do when we find a leak? ⬛
✓Correct Ans-Turn off the gas, fix the leak, retest
List 5 reasons why a leak check should be performed. ⬛
✓Correct Ans-
What is the difference between when a pressure test and a leak test should be performed?
✓Correct Ans-leak tests are pressurized with the fuel gas, the pressure test is pressurized with
⬛
an inert gas.
What is the test medium and pressure used in a leak check? ⬛
✓Correct Ans-combustable gas
, What must we do when turning the gas on? ⬛
✓Correct Ans-Perform a leak check
What size piping may require the codebooks process of purging gas piping with inert gas before
being placed into service? ⬛
✓Correct Ans-It can't contain anything listed in table 8.3.1
What size piping may require the codebooks process of purging gas piping with inert gas when
being altered ⬛
✓Correct Ans-Anything listed in table 8.3.1
Explain what should happen with the discharge of purged gases? ⬛ ✓Correct Ans-It should be
purged indoors (if allowed), or outdoors (reference for outdoor purging requirements 8.3.1.3)
What is the minimum percentage needed to pass a written test for each specialty license?
✓Correct Ans-70%
⬛
What is the first tier to the specialty license? ⬛
✓Correct Ans-Gas Piping Installer
How many hours of educational training are required for the first specialty license? ⬛
✓Correct
Ans-60 Hours (Safemec 305.02)
How many hours of on-job-training are required for the first specialty license? ⬛
✓Correct Ans-
1000 Hours (Safemec 305.02)
What is the second tier to the specialty license? ⬛
✓Correct Ans-Fuel Gas Installation Technician
How many hours of educational training are required for the second specialty license?
✓Correct Ans-100 Hours Total (Safemec 305.03)
⬛
How many hours of on-job-training are required for the second specialty license? ⬛
✓Correct
Ans-1000 On Job Training Hours (Safemec 305.03)
