Tools & Equipment Operation Flashcards

A tester's low-side gauge port becomes plugged with mineral deposits during testing. The immediate effect on a differential pressure reading will be:

Answer: An artificially high differential reading because low-side pressure cannot transmit to the gauge

A blocked low-side port traps lower pressure in the hose, making the gauge see a larger differential than actually exists across the assembly.

During a double check valve assembly (DCVA) test, the tester needs to measure the differential across Check Valve 1 alone. To do this correctly, the test cocks used are:

Answer: Test cock 1 (upstream inlet) and test cock 2 (between the two check valves)

Connecting to TC1 (inlet) and TC2 (between checks) isolates the pressure drop across Check Valve 1 only, which is the first-check differential measurement.

A tester's stopwatch shows that after initiating a test procedure, the gauge needle reached a stable reading in 45 seconds. This delay is most likely due to:

Answer: Air remaining in the hose lines slowing pressure transmission to the gauge

Residual air in hose lines compresses rather than transmitting pressure instantly, causing slow and unstable gauge response until the air is purged.

A backflow test kit used at a site with known chemical contamination should be decontaminated before being used at another site. The recommended decontamination method for rubber hoses is:

Answer: Flushing with clean water and disinfecting with a dilute bleach solution per manufacturer guidance

Flushing and disinfecting with dilute bleach (per manufacturer instructions) prevents cross-contamination between sites while preserving hose integrity.

An analog differential pressure gauge displays a reading that is repeatable but known to be 0.5 psid high based on calibration records. A tester using this gauge should:

Answer: Remove the gauge from service until it is recalibrated or repaired

A gauge with a known error should be removed from service because field corrections introduce human error and legal liability issues on official test reports.

When selecting a differential pressure gauge range for testing an RPZ assembly with a known inlet pressure of 80 psi, which gauge range is most appropriate?

Answer: 0–15 psid, because differential readings across the zone and relief valve rarely exceed 10 psid

RPZ zone differentials and relief valve opening points are typically measured in the 1–10 psid range, making a 0–15 psid gauge the optimal choice for resolution and accuracy.

A tester is testing an atmospheric vacuum breaker (AVB) but discovers the assembly has no test cocks installed. The correct course of action is to:

Answer: Document that the assembly cannot be tested due to lack of test cocks and notify the customer

Note that AVBs are typically not field testable by design, but any assembly that cannot be tested due to missing test ports must be documented and the owner notified.