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
What test pressure is typically used to pressure-test a new gas piping system before it is placed into service?
Answer: 1.5 times the operating pressure, minimum 3 psig
NFPA 54 requires new gas piping to be tested at a pressure of at least 1.5 times the operating pressure or a minimum of 3 psig, whichever is greater.
A sediment trap (drip leg) in a gas line is installed to:
Answer: Collect condensate and debris before they enter the appliance
A sediment trap collects moisture and pipe scale, preventing them from entering the gas valve or burner of the appliance.
What is the minimum burial depth for metallic gas service piping installed underground outside a building?
Answer: 18 inches
Metallic gas piping buried outside must have a minimum cover of 18 inches to protect it from damage.
Combustion air for a gas-fired water heater in a confined space can be provided by:
Answer: Two permanent openings — one near the top and one near the bottom of the enclosure
A confined space requires two openings — one within 12 inches of the ceiling and one within 12 inches of the floor — to allow adequate air circulation.
Which of the following is a correct statement about CSST (corrugated stainless steel tubing)?
Answer: CSST must be bonded and grounded per manufacturer and code requirements
CSST must be bonded to the electrical grounding system to reduce the risk of arc damage from lightning-induced surges.
A gas furnace is classified as a Category I appliance. This means its vent operates at:
Answer: Non-positive pressure and flue gases above dew point (no condensation)
Category I appliances operate at non-positive vent pressure and produce flue gases warm enough to avoid condensation in the vent.
What is the purpose of a union fitting in a gas piping system?
Answer: To permit disconnection of sections of pipe without cutting
A union allows a section of gas pipe to be disconnected for servicing or appliance removal without cutting or disassembling the entire line.