Recommended Testing - Spill-Resistant Vacuum Breakers

Note: The test kit must be held at the same level as the assembly being tested. All needle valves and bleed valves on the test kit must be closed, and flush cocks must be flushed before testing.

Test No. 1 — Differential Test

Differential pressure across the check must be 1.0 psi or above.

  1. Remove air inlet valve canopy.
  2. Connect a bleed-off valve assembly to the test cock.
  3. Connect a hose between the bleed-off valve and the high-side connection on the test kit. Open the test cock.
  4. Bleed the high side by opening the bleed-high valve (high and by-pass valves on a 3-valve test kit). Close the bleed-high valve.
  5. Close No. 2 shut-off valve, then close No. 1 shut-off valve.
  6. Open the vent valve on the SVB. If gauge reading drops, record the reading if the air inlet valve opens.
  7. SLOWLY open the bleed-high valve no more than ¼ turn, dropping the pressure slowly. Record the pressure when the air inlet valve opens. It must be 1 PSI or higher. If the inlet valve does not open, close the bleed-high valve and proceed to step 10.
  8. Fully open the bleed-high valve. Check whether the air inlet valve is fully open. Close the bleed-high valve.
  9. Close the vent valve on the SVB. SLOWLY open No. 1 shut-off valve. Proceed to TEST NO. 2.
  10. The No. 1 shut-off valve is leaking. Open and close shut-off valve No. 1 to attempt a better seal. Repeat step 7. If unsuccessful, proceed to step 11.
  11. Slowly open the bleed-off valve, dropping gauge reading to about 10 PSI. Repeat step 7. If step 7 still cannot be passed with bleed-off valve fully open, No. 1 shut-off valve must be repaired or replaced.

Test No. 2 — Air Inlet / Vent Opening Test

Air inlet must begin to open at 1.0 PSI or above and must fully open at atmospheric pressure.

  1. Close No. 1 shut-off valve. (If No. 1 shut-off valve was leaking in Test No. 1, go to step 3.)
  2. Open the vent valve on the SVB. Record the gauge reading when water stops draining from the vent valve. It must be 1 PSI or higher. Proceed to step 4.
  3. Open the vent valve on the SVB. SLOWLY open the bleed-off valve until water stops draining from the vent valve. Record the gauge reading. It must be 1 PSI or higher. If water flow cannot be stopped, No. 1 shut-off valve must be repaired or replaced.
  4. Close the test cock and vent valve. Open both shut-off valves. Remove all test equipment. Replace air inlet valve canopy. Drain test kit.
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