Backflow Assembly Field Testing Procedures Flashcards

What is the first step when performing a field test on a backflow prevention assembly?

Answer: Close the #1 shutoff valve to isolate the assembly

The #1 (upstream) shutoff valve is closed first to isolate the assembly from supply pressure before test equipment is attached.

Which test cocks are used when field testing a Reduced Pressure Zone (RPZ) assembly?

Answer: Test cocks 1, 2, and 3

RPZ assemblies have three test cocks — #1 upstream of check valve 1, #2 in the zone between the checks, and #3 downstream of check valve 2 — all three are used during testing.

What minimum differential pressure reading across check valve #1 on an RPZ assembly is required for a passing field test?

Answer: 5.0 psi

USC and AWWA standards require check valve #1 on an RPZ assembly to hold a minimum differential of 5.0 psi to pass the field test.

What is the purpose of the bypass needle valve on a backflow prevention test kit?

Answer: To slowly equalize pressure between the high and low pressure hoses

The bypass needle valve allows the tester to slowly bleed pressure between hoses for accurate differential gauge readings without spiking or damaging the gauge.

What minimum differential pressure must each check valve hold during a field test of a Double Check Valve Assembly (DCVA)?

Answer: 1.0 psi

AWWA standards require each check valve in a DCVA to hold a minimum differential pressure of 1.0 psi during field testing.

Before connecting test equipment to a backflow assembly's test cocks, the tester should verify that:

Answer: The test cocks are open and free of debris

Test cocks must be confirmed open and clear of mineral deposits or debris to ensure unobstructed pressure communication with the test kit.

During field testing, a 'tight' shutoff valve is defined as one that:

Answer: Does not allow water to pass through when in the closed position

A 'tight' shutoff valve seals completely and allows no water to pass when closed, which is a required condition for valid field testing.