Industrial Gas Fitter Licensing Exam Class B

Industrial Gas Fitter Licensing Exam Class B Practice Examination 100 Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

Q1.What is the primary purpose of a gas regulator in an appliance installation?

• Increase gas pressure
• Reduce and control gas pressure
• Filter gas contaminants
• Ensure combustion air supply

Rationale: Regulators ensure pressure is reduced and maintained at safe

operating levels for appliances.

Q2. 1 / 4

Which type of gas is lighter than air and will rise if leaked?

• Propane
• Natural gas
• Butane
• Carbon monoxide

Rationale: Natural gas is primarily methane, which is lighter than air and

rises.

Q3.The minimum pressure test for low-pressure natural gas piping typically

requires holding pressure without loss for:

• 2 minutes
• 5 minutes
• 15 minutes
• 60 minutes

Rationale: Standard testing procedures require a stable 15-minute test for

confirmation of integrity.

Q4.What is the primary cause of carbon monoxide production in gas appliances?

• Excess air 2 / 4

• High gas pressure
• Incomplete combustion
• Low humidity

Rationale: Incomplete combustion results in CO formation due to

insufficient oxygen.

Q5.

In propane systems, liquid propane becomes gas primarily due to:

• Combustion air
• Heat absorption from surrounding environment
• Mechanical pumps
• Regulator action

Rationale: External heat causes propane to vaporize inside cylinders/tanks.

Q6.What must be used when joining dissimilar metals in gas piping systems?

• Teflon tape
• Pipe cement
• Dielectric fittings
• Lead solder

Rationale: Dielectric fittings prevent galvanic corrosion between dissimilar

metals. 3 / 4

Q7.Which tool is used to verify correct manifold pressure?

• Manometer
• Manometer
• Pressure washer
• Hydrometer

Rationale: A manometer measures system or manifold gas pressure.

(Option A duplicated? Correct Answer corrected)

Revised options:

• Pressure gauge
• Manometer
• Hydrometer
• Thermocouple

Rationale: Manometers specifically measure gas pressures accurately.

Q8.

Propane gas cylinders must always be stored:

• Lying horizontally
• Inside living spaces
• Upright and secured
• Below ground level
• / 4