Gas Piping and Appliances Flashcards
7 cards from real Journeyman Plumbers Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Gas Piping and Appliances flashcards as text
A gas piping system operating at pressures above ½ psig but not exceeding 2 psig is classified as:
Answer: Medium pressure
NFPA 54 classifies gas piping at pressures above ½ psig (14 inches WC) up to 2 psig as a medium-pressure system, requiring different materials and joining methods.
What must be installed where gas piping passes through a foundation wall or concrete floor slab?
Answer: A protective sleeve or casing
Gas pipe must be sleeved where it passes through masonry or concrete to protect it from corrosion, soil movement, and to allow for expansion.
Under the International Fuel Gas Code, underground gas piping must have a minimum cover of:
Answer: 18 inches
IFGC requires a minimum of 12 inches of cover for underground gas piping in residential applications, though 18 inches is common for areas with vehicular traffic.
A pilot light that repeatedly goes out on a gas appliance most likely indicates a problem with:
Answer: The thermocouple or thermopile
The thermocouple generates a small voltage when heated by the pilot flame; if it fails or is positioned incorrectly, it causes the safety valve to close, extinguishing the pilot.
Which of the following actions is required after replacing a gas appliance regulator?
Answer: Verify outlet pressure with a manometer at the rated flow condition
After regulator replacement, outlet pressure must be verified under load conditions with a manometer to ensure it is set to the correct operating pressure (typically 3.5 inches WC for natural gas).
Gas piping that is exposed and subject to physical damage, such as in a garage or mechanical room, must be protected by:
Answer: Installing a metal guard or bollard
Physical protection such as steel guards, bollards, or pipe sleeves is required where exposed gas piping is vulnerable to damage from vehicles or equipment.
When a gas appliance is located in a confined space that is not connected to outside air, combustion air can be supplied by:
Answer: Two permanent openings: one within 12 inches of the top and one within 12 inches of the floor
NFPA 54 requires two permanent openings in a confined space — one high and one low — to allow natural convective circulation of combustion and dilution air.