Manual

Page 12 Rev. 0040304002 0410
Operating and installation instructions
Str. thr. stop valves - STEVI
®
405 / 460 (DN300-500)
7.2 Replacement of internal parts
7.2.1 Replacement of plug and stem
- Remove actuator. (Refer to operating instructions for actuator!)
Series 405:
- Loose nuts (pos. 11).
- Detach stuffing box housing (pos. 7).
- Slacken nuts (pos. 18) by about 2-3 turns.
- Extract plug (pos. 3) and stem (pos. 5).
- Drive pin (pos. 4) out with a drift.
- Unscrew stem (pos. 5) and plug (pos. 3).
Note:
In some designs the stem is locked by a spot weld,
which has to be removed with a grinding machine.
- Bolt new parts together, drill and pin them.
- Replace gasket (pos. 9).
- Assemble in reverse order.
- Secure with nuts (pos. 11) and tighten them crosswise.
(For tightening torques refer to item 7.3.1)
Series 460:
For replacement of plug and stem with bellows sealing (series 462) refer to item 7.1.3.
7.2.2 Replacement of the seat ring
Only with bodies (pos. 1) of cast iron the seat ring is screwed in.
- Remove actuator. (Refer to operating instructions for actuator!)
- Loose nuts (pos. 11).
- Detach valve top part.
- Unscrew seat ring (pos. 2) with a special wrench (can be obtained from the manufacturer).
- Clean thread and sealing taper in body (pos. 1) and apply with suitable lubricant.
- Replace respectively recondition seat ring (pos. 2).
- Install seat ring (pos. 2). (For tightening torques refer to item 7.3.2.)
- Replace gasket (pos. 9).
- Assemble valve top part.
- Secure with nuts (pos. 11) and tighten them crosswise.
(For tightening torques refer to item 7.3.1.)
ATTENTION !
Refer to item 10.0 and 11.0 before dismantling the valve.
ATTENTION !
Refer to item 10.0 and 11.0 before dismantling the valve.
Fig. 10