Gas Piping Systems Flashcards
6 cards from real 306A practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Gas Piping Systems flashcards as text
What must a plumber do if they smell gas upon entering a building?
Answer: Do not use any electrical switches, evacuate the building immediately, call the gas utility or fire department from outside
If you smell gas upon entering a building, do not operate any electrical switches (which can create sparks), evacuate immediately, and call the gas utility or fire department from a safe location outside. Even a light switch spark can ignite accumulated gas.
What is the odorant added to natural gas so that leaks can be detected by smell?
Answer: Mercaptan (methyl mercaptan or ethyl mercaptan)
Mercaptan is added to natural gas as an odorant because it has a strong, distinctive 'rotten egg' smell detectable at very low concentrations. Natural gas is odourless in its pure state, so the odorant is a critical safety addition.
What is the explosive range (flammability limits) of natural gas in air?
Answer: 5% to 15%
Natural gas is explosive when mixed with air at concentrations between 5% (lower explosive limit) and 15% (upper explosive limit). Below 5%, the mixture is too lean; above 15%, it is too rich to ignite.
According to Canadian codes, who is qualified to install and connect gas piping?
Answer: A licensed gas fitter (Class A or B) or a plumber with a gas fitting endorsement as required by the province
Gas piping installation and appliance connection must be performed by a licensed gas fitter or a plumber with the appropriate gas fitting endorsement. Provincial regulations vary but all require specific gas fitting certification due to the safety-critical nature of the work.
What is the proper procedure for decommissioning (abandoning) an unused gas pipe in a building?
Answer: Disconnect from the gas supply at a tee or manifold, remove as much pipe as practical, and seal the remaining pipe with a gas-tight cap or plug
Abandoned gas piping must be disconnected from the active gas supply at the nearest junction, removed where practical, and any remaining pipe must be sealed with a gas-tight cap or plug to prevent future accidental connections or undetected leaks.
What is the purpose of a gas leak detection system in a commercial building?
Answer: To continuously monitor for gas leaks, activate alarms, and potentially shut off the gas supply automatically if a leak is detected
A gas leak detection system uses sensors placed near gas appliances and piping to continuously monitor for gas presence in the air. If gas is detected above a set threshold, the system sounds alarms and may automatically close a solenoid valve to shut off the gas supply.