Operation Manual
ITEM
DESCRIPTION
6
54
56
55
57
58
60
61
62
63
Front Cover
Valve Housing
Spring
Valve Head Stem
Anchor Plate
Diaphragm
Nut
Bush
Circlip
Spacer Valve Preloading
13 Relief Valve
The relief valve is factory set to operate at 145
psi to partially protect the pump from over
pressurisation. The relief pressure can not be
field adjusted.
13.1 Disassembly - Relief valve
Take extreme care when removing the valve
housing as the spring has been compressed.
1. If the pump is still in the system, ensure
there is no pressure in the pump head.
2. Clean the outside of the pump and valve
casing.
3. Remove the nuts (60) and housing (54).
Loosen the nuts equally in order to move
the housing away from the rotorcase
squarely.
4. Remove the valve spring (56), spacer valve
head assembly and diaphragm (58).
13.2 Assembly - Relief valve
1. Ensure mating faces are clean and free
of product.
2. Fit the diaghragm with PTFE face towards
relief valve front cover.
3. Place the spring (56) on the valve head
(55).
4. Fit the valve head/spring assembly into
the valve housing (54).
5. Mount the housing assembly to the front
cover and retain with nuts. Tighten nuts
evenly to a torque of 15 lbft.
STP125 Page 27
