Watts 957Z - Manual (Page 3)

3
0 20 40 60 80 psi
0 138 276 413 551 kPa
3
WARNING !
Prior to servicing the relief valve, it is mandatory to shut
down water system by closing both the inlet and outlet
shutoff valves and relieving pressure within the assembly by
opening the #2, #3 and #4 test cocks.
DO NOT REMOVE SPIDER BUSHING FOR SERVICING
1. Disconnect the hose from the bottom cover plate to the relief
valve.
2. An O-ring seals the relief valve body to the main housing. It
is not necessary to tighten the connection beyond firm hand
tightening. The relief valve should be able to be removed by
unscrewing the relief valve from the housing.
3. Remove the cover plate of the relief valve by removing the four
connecting screws.
4. Remove the rubber diaphragm from the relief valve. Be
aware of how the diaphragm is configured so that it can be
reinstalled in the same manner. The hard rubber tab in the
diaphragm fits into a similar socket in the head of the piston.
(Figure 1)
5. Hold the relief valve in both hands with the threaded end
up and both thumbs on the head of the piston. Push up on
the piston until the piston shaft with the attached E-clip is
exposed. Remove the E-clip (Figure 2)
6. Remove the piston and spring from the relief valve hous-
ing and thoroughly clean all parts including the diaphragm.
Inspect all rubber parts for damage and if damaged, replace
them with new parts.
7. Reassemble the relief valve in the reverse order that it
was disassembled.
Figure 1 Figure 2
Material–Tool Requirements:
• #3 Phillips screwdriver or 5 /
16
" diameter rod, length sufficient
to span diameter of check, see Figures A and B.
• 1 /
2
– 13 x 5 fully threaded hex bolt (Service bolt).
• 3 /
4
" open end or socket wrench.
Instructions
WARNING !
Prior to servicing any Watts valve, it is mandatory to shut
down the water system by closing both the inlet and outlet
shutoff valves. After shutoff valves are closed, open test cock
#2, #3 & #4 to relieve pressure within the backflow assembly.
1. After #3 test cock has been opened to relieve pressure, re-
move #3 test cock from housing.
When repairing an 8" or 10" (200 or 250mm) device, remove
both Victaulic couplers from body. Slide the downstream Vic-
taulic coupler gasket to the downstream side of the housing.
The upstream Victaulic coupler gasket stays in place.
2. Remove checks that are to be serviced.
3. Locate the service hole and thread in the service bolt by hand
until it contacts the linkage. (Figure A)
4. Continue to thread in service bolt with the wrench until the
service hole in the linkage is aligned with the service notches
on the spring arbors. (Figure A)
5. Insert the Phillips screwdriver through the arbors and service
hole of the linkage making sure that the tip of the screwdriver
extends past the ends of the arbors by a minimum of 1 /
4
"
(6mm). (Figure B)
6. Back out the service bolt until load is transferred to the screw-
driver. Continue to back out the service bolt until
sufficient clearance is achieved to remove the complete spring
mechanism.
7. To disconnect linkage, remove retaining clip and pin (store
in a safe location for reinstallation).
8. To remove spring mechanism, grasp the screwdriver at the
center and pull complete assembly straight out and store in
a safe place.
9. Reinstall in reverse order of these instructions.
WARNING !
While the spring mechanism is removed for check servicing;
never pull the screwdriver out or off the support notches on the
arbors. Doing so may cause bodily injuries.
Maintenance Instructions
Series 957, 957RPDA, LF957RPDA
8" – 10" (200 – 250mm)
Service Relief Valve
Series 957, 957RPDA, LF957RPDA
Figure B
Figure A
Service Hole