California Gas Fitter Licensing Exam Test Questions
And Correct Answers (Verified Answers) Plus
Rationales 2025/2026 Q&A | Instant Download Pdf
1. What is the primary purpose of a gas pressure regulator in a gas system?
To reduce and control gas pressure entering an appliance
A regulator ensures gas is delivered at safe and usable pressures for
appliances.
2. What type of pipe is commonly used for underground gas lines?
Polyethylene (PE)
PE piping is flexible, corrosion-resistant, and approved for underground
use.
3. According to California Code, what must be done before starting any gas
piping installation?
Obtain a permit and notify the local building authority
Permits and inspections ensure the installation meets safety and code
requirements.
4. What is the maximum pressure allowed for a gas test on low-pressure
residential gas piping?
10 psi
Testing is usually done at 10 psi for 15 minutes to ensure there are no
leaks.
,5. What is the minimum depth for buried gas piping?
18 inches
California Plumbing Code requires gas lines to be buried at least 18 inches
to prevent damage.
6. Which fitting is used to change the direction of gas piping by 90 degrees?
Elbow
An elbow allows piping to turn sharply, commonly by 90 or 45 degrees.
7. What is the color code for natural gas piping?
Yellow
Yellow is the standard color for identifying natural gas piping in
commercial and residential applications.
8. What is the typical operating pressure for natural gas in a residential home?
¼ psi (7 inches of water column)
Residential appliances operate at low pressure, typically 7" WC or 0.25
psi.
9. What tool is used to cut black iron gas pipe?
Pipe cutter
A pipe cutter provides a clean, square cut essential for proper threading
and sealing.
10.What type of sealant is typically used on threaded gas pipe connections?
Pipe dope approved for gas use
Approved sealants prevent leaks and ensure safety in threaded
connections.
,11.A gas leak is suspected. What should be your immediate action?
Shut off the gas supply and ventilate the area
Safety requires immediate action to prevent explosion or poisoning.
12.What is the primary risk of using a gas appliance in a poorly ventilated
room?
Carbon monoxide poisoning
Incomplete combustion can produce CO, a deadly, odorless gas.
13.What must be installed on all gas appliances in earthquake-prone areas of
California?
Seismic (earthquake) shutoff valve
These valves automatically shut off gas during seismic activity to prevent
fires.
14.What is the function of a drip leg in a gas system?
To collect moisture and debris
Drip legs prevent contaminants from entering appliances and regulators.
15.Which of the following gases is typically odorized for safety reasons?
Natural gas
Mercaptan is added to natural gas so leaks can be detected by smell.
16.What does BTU stand for in relation to gas appliances?
British Thermal Unit
BTU measures the heat output; 1 BTU is the energy to heat 1 pound of
water by 1°F.
17.What is the minimum clearance around a gas water heater for combustible
materials?
, 6 inches
Adequate clearance prevents fire hazards and allows for heat dissipation.
18.Gas lines should be tested for leaks using:
A soap and water solution
Bubbles indicate escaping gas, revealing the presence of a leak.
19.What is the purpose of a gas meter?
To measure gas consumption
Meters allow utility companies to bill customers based on usage.
20.Flexible gas connectors should not exceed what length?
6 feet
To reduce stress and avoid damage, code limits connector length to 6 feet.
21.What is the correct method for supporting horizontal gas piping?
Strapping or hangers spaced per code
Supports prevent sagging and stress at joints and fittings.
22.What agency sets the safety standards for gas appliances in California?
California Energy Commission (CEC)
CEC regulates appliance safety, efficiency, and emissions.
23.What should be used to secure a gas line passing through a concrete wall?
Sleeve with proper clearance
Sleeving protects the pipe from corrosion and structural stress.
24.In California, gas shut-off valves must be:
Accessible and located within 6 feet of the appliance
Accessibility ensures fast shutoff in emergencies.
And Correct Answers (Verified Answers) Plus
Rationales 2025/2026 Q&A | Instant Download Pdf
1. What is the primary purpose of a gas pressure regulator in a gas system?
To reduce and control gas pressure entering an appliance
A regulator ensures gas is delivered at safe and usable pressures for
appliances.
2. What type of pipe is commonly used for underground gas lines?
Polyethylene (PE)
PE piping is flexible, corrosion-resistant, and approved for underground
use.
3. According to California Code, what must be done before starting any gas
piping installation?
Obtain a permit and notify the local building authority
Permits and inspections ensure the installation meets safety and code
requirements.
4. What is the maximum pressure allowed for a gas test on low-pressure
residential gas piping?
10 psi
Testing is usually done at 10 psi for 15 minutes to ensure there are no
leaks.
,5. What is the minimum depth for buried gas piping?
18 inches
California Plumbing Code requires gas lines to be buried at least 18 inches
to prevent damage.
6. Which fitting is used to change the direction of gas piping by 90 degrees?
Elbow
An elbow allows piping to turn sharply, commonly by 90 or 45 degrees.
7. What is the color code for natural gas piping?
Yellow
Yellow is the standard color for identifying natural gas piping in
commercial and residential applications.
8. What is the typical operating pressure for natural gas in a residential home?
¼ psi (7 inches of water column)
Residential appliances operate at low pressure, typically 7" WC or 0.25
psi.
9. What tool is used to cut black iron gas pipe?
Pipe cutter
A pipe cutter provides a clean, square cut essential for proper threading
and sealing.
10.What type of sealant is typically used on threaded gas pipe connections?
Pipe dope approved for gas use
Approved sealants prevent leaks and ensure safety in threaded
connections.
,11.A gas leak is suspected. What should be your immediate action?
Shut off the gas supply and ventilate the area
Safety requires immediate action to prevent explosion or poisoning.
12.What is the primary risk of using a gas appliance in a poorly ventilated
room?
Carbon monoxide poisoning
Incomplete combustion can produce CO, a deadly, odorless gas.
13.What must be installed on all gas appliances in earthquake-prone areas of
California?
Seismic (earthquake) shutoff valve
These valves automatically shut off gas during seismic activity to prevent
fires.
14.What is the function of a drip leg in a gas system?
To collect moisture and debris
Drip legs prevent contaminants from entering appliances and regulators.
15.Which of the following gases is typically odorized for safety reasons?
Natural gas
Mercaptan is added to natural gas so leaks can be detected by smell.
16.What does BTU stand for in relation to gas appliances?
British Thermal Unit
BTU measures the heat output; 1 BTU is the energy to heat 1 pound of
water by 1°F.
17.What is the minimum clearance around a gas water heater for combustible
materials?
, 6 inches
Adequate clearance prevents fire hazards and allows for heat dissipation.
18.Gas lines should be tested for leaks using:
A soap and water solution
Bubbles indicate escaping gas, revealing the presence of a leak.
19.What is the purpose of a gas meter?
To measure gas consumption
Meters allow utility companies to bill customers based on usage.
20.Flexible gas connectors should not exceed what length?
6 feet
To reduce stress and avoid damage, code limits connector length to 6 feet.
21.What is the correct method for supporting horizontal gas piping?
Strapping or hangers spaced per code
Supports prevent sagging and stress at joints and fittings.
22.What agency sets the safety standards for gas appliances in California?
California Energy Commission (CEC)
CEC regulates appliance safety, efficiency, and emissions.
23.What should be used to secure a gas line passing through a concrete wall?
Sleeve with proper clearance
Sleeving protects the pipe from corrosion and structural stress.
24.In California, gas shut-off valves must be:
Accessible and located within 6 feet of the appliance
Accessibility ensures fast shutoff in emergencies.
