Replacing The Seat And Plug - Samson 3522 Mounting And Operating Instructions

Servicing
9.4.3 Replacing the seat and
plug
NOTICE
!
Risk of damage to the facing of the seat
and plug due to incorrect service or repair.
Î Always replace both the seat and plug.
Tip
When replacing the seat and plug, we also
recommend replacing the body gasket and
the packing. See sections 9.4.1 and 9.4.2.
1. Remove the actuator from the valve. See
associated actuator documentation.
Note
To remove an actuator with "stem extends"
fail-safe action and/or with preloaded
springs, a certain signal pressure must be
applied to the actuator (see associated actu-
ator documentation). Afterwards, the signal
pressure must be removed and the air supply
disconnected again and locked.
2. Unscrew the nut (92) and lift the yoke (3)
off the bonnet (2).
3. Unscrew the bonnet (2) and lift it off the
body (1).
4. Replace the body gasket (17). See sec-
tion 9.4.1.
5. Unscrew the stem connector nut (9) and
lock nut (10) from the plug stem (5).
6. Unscrew the threaded bushing (8).
44
7. Pull the plug with plug stem (5) out of the
bonnet (2).
8. Replace the packing (15) (see sec-
tion 9.4.2)
9. Unscrew the seat (4) using a suitable
tool.
10. Apply a suitable lubricant to the thread
and the sealing cone of the new seat.
11. Screw in the new seat (4) using a suit-
able tool. Observe tightening torques.
12. Apply a suitable lubricant to all the pack-
ing parts and to the new plug stem (5).
NOTICE
!
Risk of damaging to the packing due to lu-
brication.
Î Do not use lubricant on graphite pack-
ings.
13. Slide the new plug with plug stem (5) in-
to the bonnet (2).
14. Apply a suitable lubricant to the bonnet
(2).
15. Screw bonnet (2) with plug and plug
stem (5) into the body (1). Observe tight-
ening torques.
16. Version with V-port plug: place the
flange (2) onto the valve body, making
sure that the largest V-shaped port of the
V-port plug faces towards the valve out-
let (see section 5.3.1).
17. Screw in the threaded bushing (8) and
tighten it. Observe tightening torques.
18. Place yoke (3) on the bonnet (2) and fas-
ten using the nut (92).
EB 8822 EN