Groth 1721B - Manual (Page 6)

Page 6 of 18
PREVENTIVE MAINTENANCE
Groth Corporation recommends that all service performed on a pressure/vacuum relief valve be done at the factory or a factory
authorized repair center. Trained mechanics with specialized test equipment will ensure that the valve is properly maintained
and accurately set.
It is important to regularly inspect and clean the diaphragm, guides and seating surfaces for the most effective valve
performance. Frequency of valve inspection and maintenance should be based on the experience gained in each application. It
is recommended that the valve be removed for inspection of wetted components at least once per year.
RECOMMENDED SPARE PARTS
The following spare parts should be stocked for maintenance purposes:
TABLE 3: PART NUMBER FOR RECOMMENDED SOFT GOOD SPARE PARTS
VALVE
SIZE
FEP Diaphragm
20 mil
(Spring Loaded)
FEP Diaphragm
10 mil
(Weight Loaded)
FEP Diaphragm
20 mil
(Weight Loaded)
Gasket, Outlet
Fluoropolymer
(bottom)
Gasket, Cover
Fluoropolymer
(top)
O-Ring
(machined pallet)
FKM
2" DPH1201027320 DPH1200027310 DPH1200027320 GKT1220027102 GKT1200027101
0267012U2 3" DPH1201037320 DPH1200037310 DPH1200037320 GKT1220037102 GKT1200037101
4" DPH1201047320 DPH1200047310 DPH1200047320 GKT1220047102 GKT1200047101
TABLE 4: VALVE DIAPHRAGM USAGE, BASED ON SETTING
Setting
Weight-Loaded
Spring-Loaded
< 4 OSI 4 – 8 OSI > 8 OSI
Diaphragm 10 mil 20 mil 10 mil 20 mil 10 mil 20 mil 10 mil 20 mil
Quantity 1 --- --- 1 1 1 --- 2
* Please provide the valve serial number and pressure/vacuum settings when ordering replacement parts.
TABLE 5: REPLACEMENT SPRING PART NUMBERS
Set
Range
PSIG
Carbon Steel Spring
Part Numbers
17-7 PH Stainless Steel Spring
Part Numbers
2" 3" 4" 2" 3" 4"
1.0 to 1.3 SPR1201020120 SPR1201030120 SPR1201040120 SPR1201020159 SPR1201030159 SPR1201040159
1.4 to 1.8 SPR1201020220 SPR1201030220 SPR1201040220 SPR1201020259 SPR1201030259 SPR1201040259
1.9 to 2.4 SPR1201020320 SPR1201030320 SPR1201040320 SPR1201020359 SPR1201030359 SPR1201040359
2.5 to 3.2 SPR1201020420 SPR1201030420 SPR1201040420 SPR1201020459 SPR1201030459 SPR1201040459
3.3 to 4.2 SPR1201020520 SPR1201030520 SPR1201040520 SPR1201020559 SPR1201030559 SPR1201040559
4.3 to 5.5 SPR1201020620 SPR1201030620 SPR1201040620 SPR1201020659 SPR1201030659 SPR1201040659
5.6 to 7.2 SPR1201020720 SPR1201030720 SPR1201040720 SPR1201020759 SPR1201030759 SPR1201040759
7.3 to 9.4 SPR1201020820 SPR1201030820 SPR1201040820 SPR1201020859 SPR1201030859 SPR1201040859
9.5 to 12.2 SPR1201020920 SPR1201030920 SPR1201040920 SPR1201020959 SPR1201030959 SPR1201040959
12.3 to 15.0 SPR1201021020 SPR1201031020 SPR1201041020 SPR1201021059 SPR1201031059 SPR1201041059
* To order original Groth replacement springs, find the desired pressure range from the table and select the
corresponding part number for the valve size.