Plumbing Flashcards
7 cards from real NHIE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Plumbing flashcards as text
What is the minimum slope required for a horizontal drain pipe of 3 inches or less in diameter?
Answer: 1/4 inch per foot
Horizontal drain pipes 3 inches or less in diameter require a minimum slope of 1/4 inch per foot to ensure proper drainage.
Which type of pipe is NOT approved for use as a drain, waste, and vent (DWV) pipe in most US jurisdictions?
Answer: CPVC
CPVC (chlorinated polyvinyl chloride) is approved for hot and cold water supply lines but is not approved for DWV applications.
A home inspector observes a P-trap installed below the floor slab with no access. What is the primary concern?
Answer: The trap is inaccessible for cleaning and cannot be inspected for leaks
Traps installed below the floor slab must be accessible for cleaning and inspection; inaccessible traps are a deficiency.
What does a water hammer arrestor prevent?
Answer: Pressure surges that cause banging pipes when valves close quickly
Water hammer arrestors absorb the pressure shock wave created when fast-closing valves suddenly stop water flow, preventing pipe banging.
An inspector finds a vent pipe that terminates 6 inches above the roof surface. What should be noted?
Answer: In cold climates, the termination should be at least 12 inches above the roof to prevent frost closure
In climates subject to frost, vent pipe terminations should extend at least 12 inches above the roof to reduce risk of frost closure blocking the vent.
Which condition would most likely cause a gurgling sound at a fixture when another nearby fixture is draining?
Answer: An undersized or blocked vent pipe causing siphoning of trap water seals
Gurgling at one fixture while another drains indicates an inadequate vent, causing negative pressure that siphons the trap seal and allows sewer gases to enter.
What is the purpose of a backwater valve installed in a drain line?
Answer: To prevent municipal sewer water from backing up into the home during flooding
A backwater valve (check valve) allows drain flow in one direction only, preventing sewage from backing up into the home when the municipal sewer is overwhelmed.