Plumbing Systems Inspection Flashcards

What is the minimum slope required for horizontal drain pipes 3 inches or smaller in diameter?

Answer: 1/4 inch per foot

Horizontal drain pipes 3 inches or smaller must slope at least 1/4 inch per foot to ensure proper drainage by gravity.

Which type of pipe is NOT approved for use as a water supply line under current plumbing codes?

Answer: Polybutylene

Polybutylene (PB) pipe was recalled and is no longer approved due to its tendency to fail and leak, especially at fittings.

A home inspector observes that the water heater's temperature and pressure relief valve discharge pipe terminates into a bucket. This is:

Answer: A deficiency requiring correction

The TPR valve discharge pipe must terminate within 6 inches of the floor, into a drain, or to the exterior — never into a bucket or container.

What does 'water hammer' refer to in a plumbing system?

Answer: A banging noise caused by sudden water flow stoppage

Water hammer is a pressure surge or banging noise that occurs when flowing water is abruptly stopped, often by fast-closing valves.

An inspector finds galvanized steel supply pipes in an older home. The most likely concern is:

Answer: Internal corrosion reducing water flow and pressure

Galvanized steel pipes corrode from the inside over time, restricting flow, reducing pressure, and eventually leaking.

Which condition indicates a failed wax ring seal beneath a toilet?

Answer: Water stains or soft flooring around the toilet base

Water stains, soft flooring, or odors around the toilet base indicate a failed wax ring allowing sewer gases and water to escape.

What is the purpose of an air admittance valve (AAV) in a drain system?

Answer: To allow air into the drain to prevent siphoning of trap seals without venting through the roof

An AAV is a one-way valve that opens to admit air when negative pressure develops in the drain, preventing trap siphoning without a conventional vent pipe.