Groth 1200A - Manual (Page 8)

Page 8 of 17
WARNING: When assembling a P/V valve, always use the correct length stem (as specified in
Table 3), put the pressure and vacuum pallet assemblies back in their original location and ensure
that the stem is straight and fits into the guide in the cover or weatherhood.
1. If the stem length is too long, pallet lift will be restricted; the valve will not attain its full rated
flow capacity.
2. DO NOT mix pressure/vacuum pallet assemblies. Failure to ensure that both pallet
assemblies are installed in the correct location can change the pressure and vacuum relief
settings or restrict lift of the pallet. This can cause a tank failure.
VII. VALVE TESTING PROCEDURE
General Information
1. Use only appropriate testing equipment designated by local regulations (API 2000, ISO 28300,
EN14015).
2. Calibrate all measuring devices according to device manufacturer schedule.
Seat Leakage Test (Pressure/Vacuum)
1. Test the pressure and/or vacuum seat leakage three times to verify leak tightness. Record all
test pressure and vacuum readings on the Shop Data Sheet.
2. Slowly open the Test Stand Pressure Test or Vacuum Test valve (supply pressure).
3. Adjust the appropriate flow meter to achieve the specified flow rate listed Table 4 below.
4. With the valve flowing at the flow rate indicated in Table 4, read the test stand supply pressure
using the manometer or gauge.
5. The acceptance criteria for this test are that the peak pressure attained at the specified flow
rate be at least 75% of the specified set pressure or vacuum listed on the sales order.
Perform this test three times to verify proper operation.
6. If the valve fails to meet the 75% criteria, it must be disassembled and the pallet, diaphragm or
seat repaired or replaced. The pallet assembly shall be weighed to confirm that it meets the
weight tolerance specified in the appropriate Assembly Procedure. If the pallet assembly
weight exceeds the limits, adjust the pallet weights and retest beginning at Section 4.3.2.
7. Record the test results under the Seat Leakage Test 1-3 (Pressure/Vacuum) on a Shop Data
Sheet.
Table 4 - Seat Leakage Test Criteria
Valve Size Test Flow Rate
2" - 6" 0.5 ft3/hr (0.0142 m3/hr)
8"- 12" 5.0 ft3/hr (0.1416 m3/hr)
Valve
Size
(In)
Table 3 - Stem Length
Pressure Port Vacuum Port
Piped-Away
in (cm)
Weatherhood
in (cm)
1360A
in (cm)
All Others
in (cm)
2 4.63 (11.75) 5.50 (13.97) 7.56 (19.21) 4.63 (11.75)
3 5.50 (13.97) 5.50 (13.97) 4.63 (11.75) 5.50 (13.97)
4 7.81 (19.84) 7.81 (19.84) 5.50 (13.97) 5.50 (13.97)
6 10.75 (27.31) 10.75 (27.31) 7.81 (19.84) 7.19 (18.26)
8 12.13 (30.80) 10.75 (27.31) 10.75 (27.31) 10.75 (27.31)
10 13.50 (34.29) 10.75 (27.31) 12.13 (30.80) 10.75 (27.31)
12 15.00 (38.10) 12.13 (30.80) 13.50 (34.29) 12.13 (30.80)
14 N/A N/A 15.00 (38.10) N/A