Flowserve Trunnball - Manual (Page 7)

7
8.7 Change of the upper stem sealing with o-rings
(DN450-DN800) i.e. type 898295-XXXX
Change the upper o-ring (32) if the stem sealing is leaking.
It is not necessary to remove the valve from the pipe-
works. Change the complete stem bearing according to
section 8.8 at the next service. Make sure that the valve is
pressureless.
1. Dismount the actuator. Remove the screws that
from the underside of the mountingplate of the
valve keeps the actuator in place.
2. Lift off the actuator from the valve. Remove the
keys.
3. Remove the circlip (6) and the supporting ring
(29).
4. Loosen the screws (9) and remove the washer
(30) and the anti-friction washer in PTFE (31).
5. Change the upper o-ring sealing (32). Lubricate
the new ring with silicone grease before it is
mounted.
6. Mount in reverse order.
8.8 Replacement of stem bearing and sealing
(DN450-DN800) i.e. type 898295-XXXX
Dismount the valve from the pipeworks. Please note the
instructions in sections 2 and 8.2 concerning lifting and
emptying of the valve.
1. Remove the actuator as described in section
8.7, item 1 and 2.
2. Remove the Circlip (6) and supporting ring (29).
3. Loosen the screws (9) and remove the washer
(30) and the anti-friction washer of PTFE (31).
4. Dismount the valve according to section 8.2.
5. Press the stem down into the body and remove
it.
6. Pick up the upper o-ring (32).
7. Push up both the bearing bushings (33) and the
intermediate o-ring (32).
8. Mount new bushings and o-rings after they have
been lubricated with Silicone grease. Change
also the sliding washer (34) on the stem.
9. Mount the stem and the other parts in the
reverse order.
10. Mount the valve according to section 8.3.
Before that consider to change the seatrings or
lapping of the seatrings and ball.
11. If possible, pressure test the valve and retighten
the bolts according to section 8.3.
8.9 Mounting the actuator to the valve
1. Mount the actuator. The actuator may be mounted
either in line with the connected pipes or transversely
to them. For mounting in line with the connected
pipes an intermediary plate is required
2. Ensure that both the valve and the actuator are in
the closed position before mounting the actuator.
The valve is in the closed position when the
keyway on the stem is in the direction of fl ow.
(An actuator which uses compressed air to close
the valve and a return spring to open the valve
should be mounted with the actuator and valve in the
open position.)
N.B. The direction of closure must always be
clockwise, as viewed from the actuator.
3. Before fi tting a new actuator, check that the
actuator slides easily onto the stem when the
keys are not fi tted. Check also that the keys fi t
freely into the keyways in the hollow shaft of the
actuator. Deburr if necessary. Lubricate the hollow
shaft of the actuator and push it in over the
threaded sleeve. Mount the actuator onto the stem.
Mount the bolts and nuts, and tighten them.
4. Check the function and check that the end stops
have been correctly preset. If necessary, make
adjustments.
If any accessories such as valve positioner or
limit switches should be mounted, please see the
corresponding manufacturer’s instructions for
installation and adjustment.