Groth 1660A User Manual
Page 6

Page 6 of 16
Table 3
Bolt Torque - Flat Face Flange
ANSI
150#
Drilling
Number
of
Bolts
Stud
Size
UNC
Torque
Ft. Lb.
(Kg. m)
2” 4
5/8”-11
81
(11)
3” 4
5/8”-11
106
(15)
4” 8
5/8”-11
68
(9.4)
6” 8
3/4"-10
101
(14)
8” 8
3/4"-10
142
(20)
10” 12
7/8”-9
138
(19)
12” 12
7/8”-9
179
(25)
Torque values are based on 30 PSI pressure and 
gasket factors: m = 3.5 & y = 4000 
Table 4
Bolt Torque - Raised Face Flange
ANSI
150#
Drilling
Number
of
Bolts
Stud
Size
UNC
Torque
Ft. Lb.
(Kg. m)
2”
4
5/8”-11
31 (4.3)
3”
4
5/8”-11
43 (6.0)
4”
8
5/8”-11
29 (4.0)
6”
8
3/4"-10
51 (7.1)
8”
8
3/4"-10
78 (11)
10”
12
7/8”-9
75 (10)
12”
12
7/8”-9
93 (13)
TROUBLESHOOTING GUIDE
PROBLEM
INSPECTION
SUGGESTED CORRECTIVE ACTION
Pilot Valve 
Leak 
Visual, audible or 
vapor detector 
Consult troubleshooting guide in specific pilot valve manual
Main Valve 
Actuator Leak 
Visual, audible or 
vapor detector 
Leakage at the actuator flange may be corrected by tightening 
the fasteners adjacent to the leak path. If this is not successful, 
it will be necessary to install a new gasket. Refer to page 10, 
Assembly. 
Vapor leakage 
from the valve 
body outlet. 
Visual, audible or 
vapor detector 
Leakage can occur at the valve body seat - FEP film interface; 
other leak paths are the swivel seal or a torn actuator 
diaphragm. After removing the upper actuator housing, lift the 
pallet assembly off the seat and inspect for damage to the film 
or foreign debris buildup on the seat or film. Clean or replace 
diaphragm as required. Refer to page 9, Film Seat Pallet. 
Vapor leakage 
between the 
valve body and 
tank nozzle 
Visual, audible or 
vapor detector 
Leakage between the flanges may be corrected by tightening 
the fasteners. Follow instructions listed on page 5, Installation. 
The gasket may have deteriorated due to the chemical 
environment; replace if required. The tank nozzle may be 
warped, corroded or scratched. This will require resurfacing of 
the flange face; note that a flat-faced flange is recommended to 
avoid potential damage to an aluminum valve body. 
MAINTENANCE
The 1660A POV does not require routine 
lubrication or adjustments. It should be 
checked periodically, at least twice a year, to 
confirm that the valve is functioning properly 
and that the set point is correct. Test 
connections can be provided to facilitate 
testing the valve in the field. 
The pilot valve is designed to function in a fail-
safe manner. The failure of a seal or 
diaphragm will cause pressure to be vented to 
the atmosphere; the resulting loss in pressure 
will cause the main valve to open under rising 
pressure. 
Periodic inspection for seat tightness is 
recommended to ensure compliance with local 
air pollution control requirements. If the valve 
relieves to the atmosphere, this may be 
accomplished with a gas detector calibrated 
for the principle product in the system. 
The valve will need to be periodically removed 
from the tank for inspection of diaphragms, 
gaskets and seals. When this is done, the 
valve must be carefully lifted using the lifting 
eyes on the actuator housing. Refer to 
handling instructions listed in the Installation 
section of this manual. 
