GPT Tools & Equipment Operation 3 — Questions and Answers
Question 1: Which instrument is used to verify that a gas valve is fully closed before disconnecting a gas appliance?
- Manometer
- Combustible gas detector (Correct answer)
- Pipe locator
- Pressure gauge with shutoff
Correct answer: Combustible gas detector
A combustible gas detector (sniffer) confirms no gas is present downstream of a closed valve before the technician disconnects the appliance.
Question 2: A diaphragm-type gas pressure gauge reads in inches of water column (in. WC). What is 1 psi approximately equal to?
- 14 in. WC
- 27.7 in. WC (Correct answer)
- 7.5 in. WC
- 55 in. WC
Correct answer: 27.7 in. WC
1 psi equals approximately 27.7 inches of water column, a conversion gas technicians use when working with low-pressure regulators and appliance manifolds.
Question 3: What is the correct way to store oxygen and acetylene cylinders when not in use?
- Together in the same cage for convenience
- Separated by at least 20 feet or a 5-foot non-combustible barrier (Correct answer)
- Lying horizontally to prevent tip-over
- Upright but uncapped to allow pressure release
Correct answer: Separated by at least 20 feet or a 5-foot non-combustible barrier
OSHA and CGA require oxygen and fuel-gas cylinders to be stored at least 20 feet apart or separated by a non-combustible, 5-foot-high barrier to prevent fire risk.
Question 4: When a gas technician uses a rotary pipe threader (power drive), what lubricant must be continuously applied?
- WD-40 spray lubricant
- Cutting oil (thread-cutting fluid) (Correct answer)
- SAE 30 motor oil
- Silicone grease
Correct answer: Cutting oil (thread-cutting fluid)
Thread-cutting oil (cutting fluid) cools the die, lubricates chip removal, and produces well-formed threads without galling on steel pipe.
Question 5: Which hand tool is specifically designed to tighten or remove compression-style gas fittings without damaging the fitting body?
- Channel-lock (tongue-and-groove) pliers
- Smooth-jaw flare-nut (line) wrench (Correct answer)
- Pipe wrench with serrated jaws
- Locking pliers (Vise-Grips)
Correct answer: Smooth-jaw flare-nut (line) wrench
A flare-nut wrench encircles the fitting hex on five sides, distributing torque evenly and preventing the rounding-off that pipe wrenches or pliers would cause.
Question 6: A gas technician needs to make a 90-degree bend in CSST (corrugated stainless steel tubing). What is the correct method?
- Use an approved bending guide or radius form included with the CSST system (Correct answer)
- Heat the CSST with a torch and bend by hand
- Install a threaded 90-degree elbow fitting instead of bending
- Clamp the CSST in a pipe vise and force the bend manually
Correct answer: Use an approved bending guide or radius form included with the CSST system
CSST manufacturers provide specific bending radius guides to prevent kinking or damaging the corrugations; improper bending can restrict flow or crack the jacket.
Question 7: Which PPE is mandatory when cutting or threading steel pipe with power equipment?
- Chemical splash goggles only
- Safety glasses or face shield, hearing protection, and gloves (Correct answer)
- Hard hat and steel-toe boots only
- Respirator with organic vapor cartridge
Correct answer: Safety glasses or face shield, hearing protection, and gloves
Eye protection guards against metal chips, hearing protection is required for noisy power equipment, and gloves protect against sharp edges and cutting oil.
GPT Tools & Equipment Operation 3
Which instrument is used to verify that a gas valve is fully closed before disconnecting a gas appliance?