Gas Piping and Venting 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 Venting flashcards as text
A gas appliance vent connector should slope upward toward the vent at a minimum of:
Answer: 1/4 inch per foot
Vent connectors must rise at least 1/4 inch per foot toward the vent to ensure proper draft and prevent condensate from collecting in low spots.
Propane (LP gas) differs from natural gas in that it:
Answer: Is heavier than air and tends to settle in low areas
Propane has a specific gravity greater than 1.0, so it sinks and accumulates in basements, pits, and low spots — creating a greater explosion risk than natural gas.
When multiple gas appliances share a common vent, the common vent must be sized to handle:
Answer: The total combined BTU input of all connected appliances
A common vent must be sized for the total combined BTU input of all appliances that connect to it at any time.
What is the maximum length of an unprotected flexible appliance connector used on a gas range?
Answer: 6 feet
Flexible connectors must not exceed 6 feet and must be the listed connector type appropriate for the appliance.
A gas piping system installed in a commercial kitchen must be tested at what minimum pressure after installation?
Answer: 3 psig for at least 10 minutes
Commercial gas piping systems are commonly required to hold a test pressure of at least 3 psig for a minimum of 10 minutes with no detectable pressure drop.
Which fitting is prohibited in a concealed gas piping installation?
Answer: Flexible appliance connectors run through walls or floors
Flexible appliance connectors must never be concealed in or run through walls, floors, or ceilings because they cannot be inspected or replaced easily.
What is the function of a pressure regulator installed on a gas service?
Answer: To reduce and maintain steady downstream gas pressure
A pressure regulator reduces high-pressure gas from the supply main to the lower, steady pressure required by appliances.