ASSE 5130 flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Cross-connection

Any actual or potential connection between a potable water system and a source of contamination or pollution that could allow backflow into the potable supply.

Backsiphonage

Backflow caused by negative or sub-atmospheric pressure in the supply piping, which draws nonpotable water into the potable system through a cross-connection.

Backpressure

Backflow caused by downstream pressure exceeding the supply pressure, often from pumps, boilers, elevation differences, or compressed gas systems connected to the potable line.

Pollution versus contamination

Pollution degrades water quality without creating a health hazard; contamination creates an actual health hazard and requires a higher degree of protection such as an air gap or RPZ.

Premises isolation

Containment protection installed at the service connection to protect the public main; it does not protect occupants inside the building from internal cross-connections.

Air gap

A physical separation between the supply pipe and the flood level rim of the receiving fixture, at least twice the effective opening diameter and never less than one inch.

Atmospheric vacuum breaker

A non-testable device with a check and an air inlet, installed at least six inches above the highest downstream outlet, with no downstream shutoff valve permitted.

Pressure vacuum breaker

A testable assembly with a loaded check and an air inlet, installed at least twelve inches above the highest downstream outlet, and it may have downstream shutoff valves.

Double check valve assembly

A testable assembly with two independent check valves, approved for non-health hazards such as low-hazard commercial or irrigation service connections.

Reduced pressure principle assembly

A testable assembly with two check valves and a hydraulically loaded relief valve; it is the only mechanical assembly approved for health hazards and must not be installed in a pit.

Spill-resistant vacuum breaker

A testable vacuum breaker with a check that limits discharge at the air inlet, used where a standard pressure vacuum breaker would discharge during normal operation.

Assembly versus device

An assembly is testable and has two or more shutoff valves and test cocks; a device is not testable and does not meet assembly requirements.

Differential pressure gauge

The field instrument used to test backflow assemblies; it must be calibrated, with calibration records retained, and accuracy verified before each test.

RPZ test sequence

Record supply pressure, test check one, test check two, then test the relief valve differential and verify it opens at the required threshold, typically two psi or greater.

DCVA test sequence

Test check one for tightness, then test check two, using the gauge connected through the test cocks and observing whether each check holds pressure.

PVB test

Verify the check valve holds tight and confirm the air inlet opens at the required vacuum, using the gauge to create and observe the pressure conditions.

Backsiphonage test

A test in which the gauge is used to create negative pressure by bleeding water through the high side, then observing whether the check valve holds.

Test report content

Assembly make, model, size, serial number, location, test date, tester name and certification number, gauge serial and calibration date, recorded values, and pass or fail.

RPZ continuous relief discharge

Usually caused by a fouled or damaged first check, debris on the relief seat, or a failed relief diaphragm; inspect check one before replacing the relief valve.

Check valve leakage causes

Debris on the seat, a torn seat disc, a broken spring, or a distorted clapper; manufacturer-approved repair kits restore original performance.

PVB air inlet leak

May indicate a fouled air inlet seat, a failed check, or water reaching the air inlet because a downstream shutoff was installed below the required height.

Approved repair parts

Only manufacturer-approved parts may be used; field modifications, mismatched parts, and altered springs void approval and can change the assembly's rated protection.

Post-repair retest

After any repair, the assembly must be retested and the results reported, recording the repair, parts used, tester, and date for traceability.

RPZ installation limits

Installed horizontally unless the manufacturer lists vertical approval, with clearance for testing and repair, and never in a pit, vault, or flood-prone location.

RPZ relief discharge piping

Relief valve discharge must be piped to a drain through an air gap and must not be connected directly to a drainage system; the discharge must remain visible.

PVB and AVB heights

A pressure vacuum breaker is installed at least twelve inches above the highest downstream outlet; an atmospheric vacuum breaker requires six inches and no downstream shutoff.

Site survey steps

Identify all water uses and auxiliary supplies, trace the distribution system, list cross-connections, assign degree of hazard, and specify protection for each.

Auxiliary supply protection

Wells, reclaimed water, boilers, and chemical injection systems require an air gap or RPZ at the point of connection; a double check is not acceptable for a health hazard.

Record retention

Test and repair reports are retained per jurisdiction, commonly at least three to five years and sometimes for the life of the assembly.

Tester certification

Certification must be current and issued by a recognized program; testing performed with an expired certification is generally not accepted by the water purveyor.

Confined space safety

Never enter a permit-required confined space such as a vault or pit without training, an attendant, and atmospheric testing; use proper retrieval and ventilation equipment.

Pressure safety during testing

Depressurize and bleed test cocks slowly, wear eye protection, and never loosen fittings on a pressurized assembly to avoid injury from released pressure.