Natural Gas Systems & Pipelines Flashcards
7 cards from real BGE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Natural Gas Systems & Pipelines flashcards as text
Which instrument is most commonly used by BGE technicians to detect natural gas leaks along distribution mains and service lines?
Answer: Combustible gas indicator (CGI)
A combustible gas indicator (CGI) detects the presence of flammable gas vapors in air, making it the standard tool for locating natural gas leaks.
What is the Lower Explosive Limit (LEL) of natural gas (methane) in air, below which ignition cannot occur?
Answer: 5% by volume
Natural gas (methane) has a LEL of approximately 5% by volume in air; below this concentration the mixture is too lean to ignite.
When excavating near marked underground gas facilities, what is the required hand-digging tolerance zone on each side of the marked line per PHMSA guidelines?
Answer: 18 inches
Federal and industry guidelines require hand-digging within 18 inches on each side of a marked underground gas facility to avoid striking the pipe.
What is the 'squeeze-off' procedure used for in natural gas operations?
Answer: Temporarily stopping gas flow by mechanically compressing a PE pipe
Squeeze-off uses a specialized tool to flatten and compress polyethylene pipe walls together, temporarily stopping gas flow without cutting the pipe or shutting a valve.
What action should a BGE technician take FIRST upon discovering a natural gas leak inside an occupied building?
Answer: Evacuate the building and call 911 from a safe distance
Life safety is the top priority; immediate evacuation and calling 911 from outside ensures occupants are safe before any technical response begins.
What does yellow-colored warning tape buried above an underground gas pipeline indicate to excavators?
Answer: Caution — gas line below
Yellow is the APWA (American Public Works Association) standard color for gas and oil lines; yellow warning tape signals the presence of a gas facility below.
Which type of valve is most commonly installed as the emergency shut-off device at a natural gas meter set on a residential service?
Answer: Ball valve
Ball valves provide a reliable quarter-turn shutoff with a visible open/closed indicator, making them the preferred emergency shutoff at residential meter sets.