Top Plate
The top plate holds the valve discs in place during operation. This
plate is removed to allow cleaning and replacing the valve discs.
NOTE:
The Pentair Water valve discs are made from a
chloramine resistant severe service rubber. The valve
discs will usually not need to be changed. Before
removing the top plate for valve disc service be
certain that one of the discs is not operating correctly.
To remove top plate:
Remove screws
1. Disconnect power to unit.
2. Remove cover.
3. Remove motor.
4. Remove camshaft.
5. Place unit in bypass.
6. Release water pressure by pushing the last valve disc open
with a screwdriver.
7. Any optional items may be removed.
8. Wiring harnesses should be removed.
9. Remove valve disc and spring.
10. Use a phillips screwdriver to remove the screws from the
top plate.
11. Lift the top plate off. All the valve discs can be pulled
straight out.
Inspect valve discs for wear. The sealing surface is the raised
ridge on the underside of the top shoulder.
Check each valve disc cavity in the valve for debris. Remove
any foreign objects before replacing the valve disc.
To install valve discs:
NOTE:
If the valve disc fits properly in the cavity, it will
work correctly.
1. Put the valve disc into the correct (based on shoulder size)
valve port cavity. The metal end without rubber coating
should be visible.
2. Push down on the shoulder to position the valve disc
completely into the port cavity.
3. The metal portion will be positioned straight up and the top
of the shoulder will be level with the valve.
To install the top plate:
1
5
9
13
17 15
11
7
3
4
8
12 16
18 14
10
6
2
NOTE:
All valve discs should be in position. Use the same
screws that were removed to reassemble the top plate.
WARNING:
Follow the procedure to engage the screws
with the existing threads. If the same threads
are not used, the holding power of the screw
is lost. Under pressure the valve can leak.
Screws that have the same diameter but have
different threads should not be used.
1. Position the top plate on top of the valve and over the
valve discs.
2. Insert a screw at one of the corner positions.
WARNING:
This procedure for reinserting screws must be
followed to ensure proper holding strength of
the screws.
A. Drop screw of same size and thread into the hole.
B. Use a phillips screwdriver and lightly rotate the screw
backwards (counterclockwise).
C. When the thread of the screw and the thread of the hole
match, the screw will “click” and slightly drop down.
D. The threads are lined up. Lightly rotate the screw to
tighten and engage threads.
E. Once the threads have engaged the screw can be
tightened. Minimal resistance will be present as the screw
is turned in. Resistance indicates new threads are being
formed. Back the screw out and rematch the threads.
3. Turn the screw in but do not tighten.
4. Place a second screw into the hole diagonally opposite the
first screw and turn in but do not tighten.
5. Insert another screw into one of the remaining corners and
turn it in.
6. The fourth screw goes into the hole diagonally opposite.
Turn it in.
7. Put the remaining screws in following the same criss-cross
pattern working from the ends toward the center. When all
the screws are in place they can be tightened down.
8. Start at the corner of the screw pattern and tighten that
screw. Work the same pattern from the ends toward center
and criss-crossing as each screw is tightened. Check that
each valve disc moves smoothly before replacing the spring
and camshaft.
9. Replace spring.
10. Replace camshaft and motor.
11. Replace controller and wiring harnesses.
SERVICE AND MAINTENANCE
CONTINUED
AUTOTROL
®
Logix 764 Control Performa Cv Series Valves (273, 278) Service Manual
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