Flowserve Torex butterfly valves - Manual (Page 6)

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5. Carefully examine the shaft surface to make sure
that it is completely free from scratches. Remove
any burrs from the keyways.
6. Fit two new O-rings (16 and 18) and (17 and 19)
and a new backing ring (20). Lubricate the
O-rings with Silicone grease.
7. Fit the cover (3), and spray locking compound,
such as Loctite 641, onto the bolt threads and
the tapped holes in the valve body. Tighten the
bolts.
9.8 To inspect and replace the upper
shaft seal of graphite type
The stuffing box usually requires inspection and
adjustment after the valve has been taken into service.
After a certain period of time in service, it may sometimes
also be necessary to repack the valve.
Ensure that the valve is not under pressure.
1. Remove the actuator as described in section
9.7.
2. Remove the nuts (29) and remove the gland
bush (23) and the packing (21 - 22).
3. Clean the surfaces of the shaft, gland bush (23)
and recess in the valve body.
4. Carefully examine the surface of the shaft which
must be completely free from marks and
scratches.
5. Fit new packing (21 - 22). Then fit the gland
bush (23) and the nuts (29).
6. Tighten the nuts (29) sufficiently to ensure that
the packing is correctly seated and that it is in
contact with both the shaft and the valve body.
Note: Check the condition of the packing and, after the
valve has been taken into service, retighten the nuts (29),
if necessary.
9.9 To change the packing, item no. 9
Ensure that the valve is not under pressure.
1. Remove the set screw (7) and gasket (9).
2. Carefully clean the set screw (7) and the lower,
loadcarrying part of the shaft (5).
3. Fit a new gasket (9).
4. Spray locking compound, such as Loctite 641,
onto the screw threads in the valve body.
5. Fit and tighten the set screw (7).
10. To replace the shafts and the
valve disc
If the valve disc (2) or shafts (4) and (5) have been
damaged and need replacing, the valve must be sent
to NAF for repair, since special tools and fixtures are
necessary for correct assembly.
11. Fitting the actuator to the valve
1. The actuator can be mounted directly on the
valve. The mounting flange and the shaft of the
valve follow the NAF standard for securing the
actuator.
2. Turn the valve to the closed position (clockwise),
although without applying a closing torque. (The
valve disc should then only just be in contact
with the seal ring in the valve body.)
3. Fit the actuator. The actuator should be in the
”almost closed” position, i.e. 5 - 8° of the
rotary travel of the actuator should remain before
the end position. Adjust the end position stop of
the actuator to this almost closed position.
4. Connect the compressed air supply to the
actuator. (Applies to pneumatic actuators.)