ARI Armaturen STEVI 463 EN - Manual (Page 9)

Rev. 0040318000 0410 Page 9
Operating and installation instructions
3-way control valves - STEVI
®
423 / 463
7.1.2 Bellows seal design
If the stem leaks the bellows seal (pos. 25.3) is defective. The leak can initially be stopped
by tightening the screw joint (pos. 25.17) respectively sleeve nut (pos. 25.16).
Stem and bellows seal (pos. 20.3) can only be replaced together.
Replacement of bellows seals:
- Remove the actuator. (Refer to operating instructions for actuator!)
- Slacken screw joint (pos. 20.17) respectively sleeve nut
(pos. 20.16) by about one turn.
- Loose nuts (pos. 29).
- Lift bellows housing (pos. 25.1).
- Drive pin (pos. 16) out with a drift.
7.1.2.1 Bellows seal and mixing plug
- Loose nuts (pos. 7 bottom).
- Detach the bottom flange (pos. 3).
- Unscrew plug (pos. 8) with adapter (pos. 15).
- Loose nuts (pos. 29).
- Detach bellows assembly (pos. 25).
- Loose nuts (pos. 25.8).
- Detach stuffing box housing (pos. 25.13) resp.
mounting bonnet (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 2 gaskets
(pos. 5).
- Assemble in reverse order .
- Secure with nuts (pos. 7, 25.8 and 29) and
tighten them crosswise.
(For tightening torques refer to point 7.3.1.)
- Tighten screw joint (pos. 25.17) respectively
sleeve nut (pos. 25.16) gradually up to
tightness of the stuffing box packing (pos.
25.10).
ATTENION !
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. 10: Series 463 with mixing plug
(top)
(top)
(bottom)
(bottom)