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 distance a vent pipe termination must be from an operable window or door opening?
Answer: 3 feet
Vent pipe terminations must be at least 3 feet away from any opening (window, door, or air intake) to prevent sewer gases from entering the building.
A home inspector observes a washing machine drain hose inserted into a standpipe that is only 18 inches tall. What is the concern?
Answer: The standpipe is too short and may allow wastewater to overflow or siphon
A washing machine standpipe must be at least 18–42 inches tall (per most codes), and the drain hose must not be inserted so deep as to create a seal that causes siphoning.
What is the most likely cause of low water pressure at a single fixture while pressure at other fixtures is normal?
Answer: A partially closed supply valve or mineral-clogged aerator at that fixture
When pressure is low at only one fixture, a locally restricted aerator or partially closed valve is the most probable cause.
During a home inspection, a gas water heater is found in a bedroom closet without any combustion air provisions. What is the primary hazard?
Answer: Insufficient combustion air can cause incomplete combustion, producing carbon monoxide
A gas appliance in a confined space without adequate combustion air can produce carbon monoxide from incomplete combustion, which is a life-safety hazard.
Which of the following is a required safety feature on a temperature and pressure relief (TPR) valve discharge pipe?
Answer: The pipe must terminate within 6 inches of the floor or to the exterior, not be capped or reduced in size
TPR valve discharge pipes must terminate near the floor or exterior to safely direct scalding water away from occupants, and must never be capped, plugged, or reduced.
An inspector finds gray plastic pipe used for supply lines throughout a 1990s home. What is the significance?
Answer: This is likely polybutylene (PB) pipe, which is prone to failure and was the subject of a class-action settlement
Polybutylene pipe, common in homes built 1978–1995, has a history of fitting and pipe failures and should be noted as a material of concern.
What is the purpose of an air gap at a dishwasher drain connection?
Answer: To prevent contaminated wastewater from siphoning back into the dishwasher and potable water supply
An air gap physically separates the dishwasher drain from the drain system, preventing backflow of contaminated wastewater into the dishwasher or supply system.