Installation Techniques Flashcards
7 cards from real PC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Installation Techniques flashcards as text
When running gas pipe through an unventilated chase or interior wall cavity, which pipe material is acceptable under most US codes?
Answer: Black steel pipe
Black steel pipe (Schedule 40) is the standard material accepted for gas piping inside wall cavities; CSST requires proper bonding and CSST in some areas must be bonded at every appliance.
What is the primary reason a p-trap must have a water seal of at least 2 inches?
Answer: To maintain enough water to block sewer gases from entering the building
The 2-inch minimum water seal in a p-trap creates a barrier that blocks toxic and flammable sewer gases such as hydrogen sulfide and methane from entering the occupied space.
When installing a dishwasher drain, where must the drain hose be routed before connecting to the disposal or drain?
Answer: Through a high loop or air gap at the underside of the countertop
The dishwasher drain hose must form a high loop secured at the underside of the countertop, or connect through an air gap device, to prevent backflow of wastewater into the dishwasher.
A plumber is installing a 2-inch vent through a roof with a 4:12 pitch in a climate with snow. What is the minimum vent extension height above the roof?
Answer: 24 inches
In climates subject to frost and snow, plumbing codes require vent pipes to extend at least 24 inches (2 feet) above the roof surface to stay above typical snow accumulation.
What is the correct procedure when installing a gate valve on a water main inside a building?
Answer: Install with the stem pointing upward or horizontal, never downward
Gate valves must be installed with the stem pointing upward or horizontal; a downward-pointing stem can trap sediment in the bonnet and cause the packing to deteriorate prematurely.
When using a pneumatic pressure test on a water supply system, what is the maximum test pressure permitted by the IPC for plastic piping?
Answer: 100 PSI
The IPC limits air pressure testing of plastic water supply piping to 50 PSI maximum because plastic pipe can fail explosively under high-pressure air, unlike a hydrostatic failure.
When roughing in a floor drain in a concrete slab, what must be installed around the drain pipe to allow for concrete shrinkage and movement?
Answer: A compressible foam sleeve or isolation material around the pipe
A compressible foam sleeve or isolation wrap around the drain pipe prevents concrete shrinkage and thermal movement from cracking the pipe or breaking the joint as the slab shifts.