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Copyright © AVK Holding A/S, original version, rev. 2, 30-Oct-2019
9.1 Operation
The valve is opened and closed by switching the solenoid valve. Be careful not to operate it in a
manner that makes it close too quickly and cause water hammer.
In case water hammer occurs the moving of the cylinder can be slowed by adjusting the
throttles in the outlet from the solenoid valve.
9.2 Maintenance
During normal operation no maintenance is necessary.
9.3 Replace stuffing box shaft seal
The seal consists of three identical U-form rubber lip seals (23) and a wiper ring (22) mounted in
series. The middle rubber seal ring has a spacer ring (24) for support.
Fig. 4, stuffing box
1. Isolate the valve and release pressure in the piping system
2. Remove the hot melt seal to uncover and unscrew the bonnet bolts and lift off the
complete bonnet assembly, including wedge and actuator
3. Unscrew the stem adaptor set screw (9) and unscrew the wedge-to-stem adapter from
the actuator rod (28)
4. Unscrew the four nuts (17) holding the actuator and separate the actuator from the
bonnet assembly
5. Unscrew the two bolts (26) holding the stuffing box
6. Press the old seal rings out of the stuffing box with a screwdriver or similar; note that the
seals will be destroyed in this process
7. Insert new seals by pressing them into the stuffing box
a. Use a ring mandrel Ø34/43 mm for DN 65-150 and Ø41/47 mm for DN 200-400
b. Make sure the opening in the U-form is facing outward as shown on fig. 4
c. Be sure to fit the spacer ring (24) in the no. 2 seal ring
d. Replace the flat gasket (20).
8. Assemble in reverse sequence
9. Tighten the bonnet bolts to approx. 20 to 30 Nm following a diagonal sequence as
shown for an 8 bolt example on fig. 5
10. Repeat step 9 with the torque wrench set to 50 Nm