Minnesota Gas Installer Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary purpose of a sediment trap in a gas piping
system?
A. To increase gas pressure
B. To remove moisture from the gas meter
C. To collect debris and condensate before it enters appliances
D. To regulate gas flow to appliances
Sediment traps are installed to capture dirt, scale, and condensate that
may travel through the gas piping system. This helps protect appliance
controls and burners from damage or malfunction.
2. Which type of gas is lighter than air?
A. Propane
B. Butane
,C. Fuel oil vapor
D. Natural gas
Natural gas is lighter than air and tends to rise when released. Propane is
heavier than air and tends to collect in low areas.
3. What is the minimum test pressure commonly required for a
residential gas piping rough-in test?
A. 1 psi
B. 3 psi
C. 10 psi
D. 25 psi
Residential gas piping systems are typically pressure tested at no less than
3 psi to verify system integrity before operation. Local code requirements
may vary.
4. Which instrument is commonly used to measure gas pressure in
inches of water column?
A. Hygrometer
B. Ammeter
C. Thermocouple
D. Manometer
,A manometer measures low gas pressures, especially those expressed in
inches of water column used in gas appliance systems.
5. What is the primary hazard associated with incomplete combustion?
A. Excess oxygen production
B. Water leakage
C. Carbon monoxide formation
D. Reduced pipe pressure
Incomplete combustion produces carbon monoxide, a toxic and potentially
fatal gas caused by insufficient oxygen during burning.
6. Which piping material is commonly prohibited for underground gas
piping unless specifically approved?
A. Polyethylene
B. Corrugated stainless steel tubing
C. Copper tubing
D. Galvanized steel pipe
Galvanized steel pipe can flake internally and may react with certain gas
compositions, making it unsuitable in many gas installations unless
approved.
7. What is the purpose of a gas regulator?
, A. To filter impurities
B. To reduce gas pressure to a usable level
C. To increase gas temperature
D. To measure gas flow
Gas regulators reduce incoming gas pressure to levels suitable for
appliances and safe system operation.
8. When purging a gas line, what is the major safety concern?
A. Water contamination
B. Pipe corrosion
C. Accumulation of combustible gas-air mixtures
D. Excessive gas cooling
Improper purging can create explosive gas-air mixtures. Proper ventilation
and ignition source control are essential during purging operations.
9. Which valve is commonly installed immediately before an appliance?
A. Relief valve
B. Gate valve
C. Globe valve
D. Shutoff valve
An accessible shutoff valve allows quick isolation of the appliance for
maintenance or emergencies.
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary purpose of a sediment trap in a gas piping
system?
A. To increase gas pressure
B. To remove moisture from the gas meter
C. To collect debris and condensate before it enters appliances
D. To regulate gas flow to appliances
Sediment traps are installed to capture dirt, scale, and condensate that
may travel through the gas piping system. This helps protect appliance
controls and burners from damage or malfunction.
2. Which type of gas is lighter than air?
A. Propane
B. Butane
,C. Fuel oil vapor
D. Natural gas
Natural gas is lighter than air and tends to rise when released. Propane is
heavier than air and tends to collect in low areas.
3. What is the minimum test pressure commonly required for a
residential gas piping rough-in test?
A. 1 psi
B. 3 psi
C. 10 psi
D. 25 psi
Residential gas piping systems are typically pressure tested at no less than
3 psi to verify system integrity before operation. Local code requirements
may vary.
4. Which instrument is commonly used to measure gas pressure in
inches of water column?
A. Hygrometer
B. Ammeter
C. Thermocouple
D. Manometer
,A manometer measures low gas pressures, especially those expressed in
inches of water column used in gas appliance systems.
5. What is the primary hazard associated with incomplete combustion?
A. Excess oxygen production
B. Water leakage
C. Carbon monoxide formation
D. Reduced pipe pressure
Incomplete combustion produces carbon monoxide, a toxic and potentially
fatal gas caused by insufficient oxygen during burning.
6. Which piping material is commonly prohibited for underground gas
piping unless specifically approved?
A. Polyethylene
B. Corrugated stainless steel tubing
C. Copper tubing
D. Galvanized steel pipe
Galvanized steel pipe can flake internally and may react with certain gas
compositions, making it unsuitable in many gas installations unless
approved.
7. What is the purpose of a gas regulator?
, A. To filter impurities
B. To reduce gas pressure to a usable level
C. To increase gas temperature
D. To measure gas flow
Gas regulators reduce incoming gas pressure to levels suitable for
appliances and safe system operation.
8. When purging a gas line, what is the major safety concern?
A. Water contamination
B. Pipe corrosion
C. Accumulation of combustible gas-air mixtures
D. Excessive gas cooling
Improper purging can create explosive gas-air mixtures. Proper ventilation
and ignition source control are essential during purging operations.
9. Which valve is commonly installed immediately before an appliance?
A. Relief valve
B. Gate valve
C. Globe valve
D. Shutoff valve
An accessible shutoff valve allows quick isolation of the appliance for
maintenance or emergencies.
