Flowserve Trunnball User Manual

Page 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.