- Certified Irrigation Technician Backflow Prevention Devices Flashcards

A Spill-Resistant Pressure Vacuum Breaker (SVB) differs from a standard PVB primarily because it:

Answer: Contains a spring-loaded check valve and air inlet that minimizes water spillage during normal operation

The SVB is designed with a spring-loaded check valve and air inlet that prevents water spillage during normal operation, unlike a standard PVB which may drip from its air inlet. However, both devices protect only against backsiphonage and must be installed above the highest downstream outlet.

When performing a field test on an RPZ assembly, what is the correct order of testing?

Answer: First check, relief valve, second check

The standard test procedure for an RPZ assembly is: first check valve, then relief valve, then second check valve. This sequence is specified by the USC Foundation for Cross-Connection Control and Hydraulic Research and ensures accurate readings.

An irrigation system with a booster pump that can develop pressures exceeding the supply pressure requires which minimum level of backflow protection?

Answer: Double Check Valve Assembly

A booster pump can create backpressure conditions where downstream pressure exceeds supply pressure. A DCVA or RPZ is required because both protect against backpressure. PVBs and AVBs only protect against backsiphonage and would fail under backpressure conditions.

What is the primary purpose of the test cocks on a testable backflow prevention assembly?

Answer: To provide connection points for differential pressure testing equipment

Test cocks are small valved ports on the assembly that allow a certified tester to connect differential pressure gauges. These connection points enable measurement of the pressure differentials across check valves and the relief valve opening point.

In a cross-connection control program, an irrigation system connected to a potable water supply is classified as what type of hazard if only clean water is used with no chemical injection?

Answer: Low hazard (pollution)

An irrigation system using only clean potable water without chemical injection is typically classified as a low hazard (pollution) because the water in the piping may become non-potable due to stagnation, heat, or contact with soil, but does not pose a health threat. A DCVA is the minimum protection for low-hazard connections.

Which of the following statements about Atmospheric Vacuum Breakers (AVBs) is correct?

Answer: They must be installed on every zone downstream of the zone valve

AVBs must be installed downstream of the last valve on each zone because they cannot handle continuous pressure. They must be installed at least 6 inches above the highest downstream outlet and are designed for non-continuous pressure applications only.