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 reduced pressure zone assembly must be installed so that the relief valve outlet is:
Answer: At least 12 inches above the flood level rim of the nearest receptor
The RPZ relief valve outlet must discharge at least 12 inches above the flood level rim of any receptor or floor to prevent backflow through the discharge port.
Which scenario represents backsiphonage rather than backpressure?
Answer: A water main break causes a vacuum in the supply line
Backsiphonage occurs when negative pressure (vacuum) in the supply line siphons contaminants from a downstream source back into the potable supply.
What ASSE standard covers pressure vacuum breakers (PVBs) for irrigation applications?
Answer: ASSE 1020
ASSE 1020 is the standard for pressure vacuum breaker (PVB) assemblies used in irrigation and other plumbing applications.
When should a plumber NOT use a pressure vacuum breaker on an irrigation system?
Answer: When chemicals or fertilizers are injected into the system
Chemical injection (fertilizers, pesticides) creates a health hazard requiring an RPZ assembly — a PVB is insufficient for this level of risk.
A backflow preventer installed on a carbonated beverage dispenser connection to the potable water line requires which device?
Answer: Dual check valve with atmospheric vent (ASSE 1022)
Carbonated beverage dispensers require an ASSE 1022 dual check valve with atmospheric vent because carbonation creates backpressure risk without a health hazard.
Which of the following is a requirement for the installation location of a testable backflow assembly such as an RPZ?
Answer: It must be accessible for testing and maintenance
All testable backflow prevention assemblies must be installed in accessible locations so certified testers can operate test cocks and valves without obstruction.
What is the purpose of test cocks on a reduced pressure zone (RPZ) assembly?
Answer: To allow a certified tester to measure differential pressure across each check valve
Test cocks provide connection points for differential pressure gauges so a certified tester can verify each check valve and the relief valve are functioning correctly.