Backflow Prevention and Safety Flashcards
7 cards from real Master Plumber Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Backflow Prevention and Safety flashcards as text
A cross-connection survey identifies a dental office with a unit that has water lines running into patient rinse bowls. What level of hazard does this represent?
Answer: High hazard — RPZ or air gap required
Dental equipment can introduce biological and chemical contaminants into the water supply, classifying it as a high-hazard connection requiring RPZ or air gap protection.
Which standard governs the testing and certification of backflow prevention assembly testers in the United States?
Answer: ASSE 5010-2019
ASSE 5010-2019 (formerly 5000) is the professional qualifications standard for backflow prevention assembly testers in the US.
An irrigation system services both a potable-water zone and a reclaimed water zone on the same property. Which code requirement applies to the potable water supply connection?
Answer: An RPZ assembly is required to prevent reclaimed water from entering the potable supply
Reclaimed (recycled) water is considered a high-hazard contaminant; an RPZ assembly is required on the potable supply connection to prevent cross-contamination.
A hose connection vacuum breaker (HCVB) is designed to protect against which specific hazard?
Answer: Backsiphonage through a garden hose connected to a potable hose bib
An HCVB (ASSE 1011) is a simple device that screws onto a hose bib to prevent backsiphonage when a hose is submerged in a non-potable source.
When installing an RPZ assembly in a pit or vault, what is the most critical code concern?
Answer: The vault must be classified as a confined space and the relief valve must not be submerged
Installing an RPZ in a pit creates confined-space hazards for maintenance workers and risks submerging the relief valve in water, which would allow contamination to enter the zone.
Which condition would cause a double check valve assembly (DCVA) to fail a field test?
Answer: Either check valve fails to hold against a closed downstream condition
A DCVA fails the field test if either check valve leaks when pressure is applied in the reverse direction, indicating the check is fouled or worn.
Under the International Plumbing Code (IPC), which type of backflow protection is required for a water connection to a solar thermal heating system that uses antifreeze fluid?
Answer: Reduced pressure zone (RPZ) assembly
Antifreeze is a toxic chemical, classifying a solar thermal system using it as a high-hazard cross-connection requiring an RPZ assembly on the potable water supply.