Gas Piping Systems Flashcards
7 cards from real Master Plumber 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 Systems flashcards as text
What is the maximum allowable pressure drop for a low-pressure gas system serving residential appliances?
Answer: 0.5 inch water column
NFPA 54 allows a maximum pressure drop of 0.5 inch water column for low-pressure residential gas systems.
Which material is NOT approved for use as a gas supply line inside a residential building?
Answer: Galvanized steel pipe
Galvanized steel pipe is not approved for interior gas piping because zinc coating can flake off and clog gas orifices.
A gas dryer requires a shutoff valve located within how many feet of the appliance?
Answer: 6 feet
The International Fuel Gas Code requires an appliance shutoff valve within 6 feet of the gas appliance it serves.
What type of joint compound (pipe dope) is acceptable for gas piping connections?
Answer: Only compounds listed and approved for gas use
Only thread sealants specifically listed and approved for gas service should be used on gas piping joints.
When sizing a gas lateral, which factor is NOT used in the calculation?
Answer: Color of the pipe material
Pipe sizing calculations are based on BTU demand, pipe length, and available pressure — pipe color has no bearing on capacity.
CSST (corrugated stainless steel tubing) must be bonded to the electrical grounding system primarily to protect against:
Answer: Lightning-induced arc damage
CSST bonding is required because lightning-induced electrical surges can arc through the thin corrugated walls and cause gas leaks.
What is the minimum burial depth for underground gas service piping in areas subject to physical damage?
Answer: 18 inches
NFPA 54 requires underground gas piping to be buried at least 18 inches deep in areas where physical damage could occur.