ARI Armaturen STEVI 462 EN - Manual (Page 9)

Rev. 0040307000 0410 Page 9
Operating and installation instructions
Straight through control valves - STEVI
®
422 / 462
7.1.2 Bellows seal design
If the stem leaks, the bellows seal is defective. The leak can initially be stopped by
tightening the sleeve nut (pos. 25.16).
Stem and bellows (pos. 25.3) can only be replaced together.
Replacement of bellows seal:
- Remove actuator.
(Refer to operating instructions for actuator!)
- Loose nuts (pos. 7).
- Detach bellows assembly (pos. 25) incl. stuffing box
housing (pos. 12).
- Slacken screw joint (pos. 25.17) resp. sleeve nut (pos.
25.16) by about one turn.
- Loose nuts (pos. 29).
- Lift bellows housing (pos. 22.1).
- Drive spring pin (pos. 16) out with a drift.
- Unscrew stem adapter (pos. 15) with plug (pos. 8).
- Loose nuts (pos. 25.8).
- Detach mounting bonnet (pos. 25.2) or stuffing box
housing (pos. 25.2).
- Extract stem-/bellows unit (pos. 25.3) from the bellows
housing (pos. 25.1).
- Bolt new parts together and drill them.
- Replace 2 gaskets (pos. 25.6) and 1 gasket (pos. 5).
- Assemble in reverse order.
- Secure with nuts (pos. 7, 25.8 and 29) and tighten them
crosswise.
(For tightening torques refer to item 7.3.1)
- Tighten the screw joint (pos. 22.17) resp. the sleeve nut (pos. 22.16) gradually up to
tightness of the stuffing box packing (pos. 22.10).
ATTENTION !
Refer to item 10.0 and 11.0 before
dismantling the valve.
ATTENTION !
- Ensure that the torsion lock is
correctly positioned when inserting
new stem/bellows unit. Introduce the
grooved pin (pos. 25.9) into the
torsion lock groove.
Make sure it runs smoothly!
Fig. 9: Series 462