Groth 1200A - Manual (Page 8)

7
TEST PROCEDURE:
1. A chart showing nominal pallet assembly
weights for three common units of pressure is
shown below in Table 4. Before starting to
reassemble a valve, calculate the nominal
pressure and vacuum pallet assembly weights.
Weigh both pallet assemblies to ensure the correct
settings.
2. After final assembly, mount the valve on a Tank
Vent Test Stand (TVTS) and slowly raise the
pressure at the flow rate specified below:
Valve Size Test Flow Rate
2" - 6" 0.5 SCFH
8"- 12" 5.0 SCFH
ACCEPTANCE CRITERIA: The pressure gauge
shall maintain a pressure equal to or greater than
75% of set pressure for a one minute period while
the specified flow rate is maintained.
3. If the valve fails to meet the 75% criteria, it must
be disassembled and the seat, pallet, and or
diaphragms repaired or replaced.
4. Complete a Test Report indicating the actual
pallet assembly weight and the peak pressure
achieved at the specified Test Flow Rate.
5. A copy of the Test Report shall be maintained
with the Valve Maintenance Records.
TABLE 4 - Nominal Pallet Assembly Weight Per Unit of Pressure (*)
Valve Size
SET 2" 3" 4" 6" 8" 10" 12"
[Lb.] [kg] [Lb.] [kg] [Lb.] [kg] [Lb.] [kg] [Lb.] [kg] [Lb.] [kg] [Lb.] [kg]
1.0 OSI 0.22 0.10 0.48 0.22 0.84 0.38 1.84 0.84 3.24 1.47 5.03 2.29 7.22 3.28
1.0 IN WC 0.13 0.06 0.28 0.13 0.48 0.22 1.06 0.48 1.87 0.85 2.91 1.32 4.17 1.90
1.0 mbar 0.05 0.02 0.11 0.05 0.19 0.09 0.43 0.19 0.75 0.34 1.17 0.53 1.67 0.76
Example: Pallet Assembly Weight Calculation (PAW)
6" Valve set at 7.5 OSI
Read weight at 1.0 OSI from table Weight = 1.84 Lb.
Multiple weight by set pressure PAW (*)= 1.84 x 7.5 = 13.8 Lb.
(*) = Includes pallet, retainer plate, stem, diaphragm, weight plates (integral w/ pallet) & fasteners.