Griffco Valve HP-Series - Manual (Page 3)

INSTALLATION:
Pressure Relief Valve:
Installation should be made as close to the chemical pump discharge valve as possible, without
any equipment, especially shut-off valves, between the valve and the pump. Direction of flow must
be in the bottom of the valve and relieve out the side. All valves are factory set at 350 psi, unless
requested otherwise by the customer. Field adjustment is possible with the adjustment screw.
Turn clockwise to increase pressure.
The optimum installation for the relief valve is to vent the relief port back to the chemical tank, or
directly to a containment area. However if this is not possible, the relief port can be piped back
into the suction side of the pump. This will apply the suction pressure to the relief port. To
compensate, divide the suction pressure by 4 and add this pressure to the relief valve setting.
Always test the relief valve under normal system operating conditions to ensure it is set properly.
MAINTENANCE:
The pressure relief valves require a minimal amount of maintenance to keep the valves in
operation. Periodic replacement of the diaphragm and piston are required. To facilitate inspection
and replacement, the valve layout is such that removal of the diaphragm and piston can be done
without taking the valve out of the chemical line.
Caution: Ensure the system is not under pressure and that the chemical lines are flushed
with water before disassembly.
Unscrew the pressure adjustment screw to remove the pressure from the valve. Remove the 4
bolts and lift off the valve top.
After the diaphragm, piston and the valve seat have been inspected and replaced if necessary
check the adjustment spring. Make sure there is no rust or corrosion. Replace the spring and the
support disc into the valve top, slide the top back over the valve body and align the bolt holes.
Snug down the four bolts. Screw in the adjustment screw to approximately the same position as it
was prior to disassembly. If an exact pressure setting is required or a different pressure is desired
a pressure gauge should be used to verify the setting. Pressure can be increased by turning the
pressure adjustment screw clockwise.
DIMENSIONS :
A
C
B
D
In le t P o rt
D A B C
1/4” 4.23 2.375 1.125
3/8” 4.23 2.375 1.125
1/2" 4.23 2.375 1.125
3/4” 5.89 3.50 1.375
1” 5.89 3.50 1.375
NOTE: Dimensions are general. See dimension sheets
for exact sizes of various material valves.