Groth 1200A - Manual (Page 9)

Page 9 of 17
Set Pressure and/or Vacuum Test
1. Test the set pressure and/or vacuum three times to verify proper operation. Record all test
pressure and vacuum readings on the Shop Data Sheet.
2. With the valve mounted on the test stand from previous test, slowly increase the pressure
while monitoring the air supply pressure flow rate. For vacuum tests, the block valve is opened
sufficiently to allow a steady increase in vacuum condition. As the setting is approached,
continue to open the valve.
3. The set pressure (vacuum) will be the point at which the test pressure (vacuum) does not
increase with a corresponding increase in flow rate. Normally, at this point, the test pressure
(vacuum) will fluctuate up and down as the valve relieves, while the flow rate remains steady.
The set pressure or set vacuum is the maximum pressure or vacuum achieved during the test.
4. Repeat this test two more times to achieve a total of three measurements of set pressure and
vacuum.
5. The acceptable tolerance range for set pressure (vacuum) is +/- 10%. All three test results
must fall within the specified tolerances for the pressure and vacuum settings listed on the
sales order. Record the three set pressures and vacuum measurements on the Shop Data
Sheet.
6. If all three set test values are not within the allowable tolerance, disassemble the valve; inspect
the pallet, seat and diaphragms. It may be necessary to lap the seat or replace one or more
components. If the pallet weight falls within the limits, but still exceeds either the pressure or
vacuum setting tolerance, consult Groth Corporation.
VIII. SOFT GOODS KITS
Soft Goods Kits are available upon request. Kits include all diaphragms, O-Rings, and gaskets to
repair a valve. Kits are based on Model Number, Size, and Material. The kits are built to
accommodate all pressure/vacuum relief weight loaded valves, spring/weight loaded valves, and
spring loaded valves, therefore, parts not used on a particular valve may be provided. The kits
only apply to valves manufactured since 1992. Please contact Groth Corporation with the Serial
Number, Model Number, Size, and Material to be recommended the appropriate Kit for your valve.
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