ARI Armaturen STEVI 460 DN 15-250 EN - Manual (Page 12)

Page 12 Rev. 0040304000 0410
Operating and installation instructions
Straight thr. stop valves - STEVI
®
405 / 460 (DN15-250)
7.1.3 Bellows seal design
If the stem leaks, the bellows seal (pos. 20.3) is defective. The leak can initially be stopped
by tightening the screw joint (pos. 20.17).
Stem and bellows (pos. 20.3) can only be replaced together.
Replacement of bellows seals:
- Remove actuator. (Refer to operating instructions
for actuator!)
DN15-150:
- Loose nuts (pos. 11).
- Detach bellows assembly (pos. 20).
- Slacken screw joint (pos. 20.17) by about one
turn.
- Press stem/bellows-unit (pos. 20.3) down.
- Drive spring pin (pos. 26) out with a drift.
- Unscrew stem adapter (pos. 25) with plug
(pos. 3).
- Loose nuts (pos. 20.8).
- Detach mounting bonnet (pos. 20.2)
- Extract stem/bellows-unit (pos. 20.3) from the
bellows housing (pos. 20.1).
- Bolt new parts together and drill them.
- Replace 2 gaskets (pos. 20.6) and 1 gasket
(pos. 9).
- Assemble in reverse order.
- Secure with nuts (pos. 10 and pos. 20.8) and
tighten them crosswise. (For tightening torques
refer to item 7.3)
- Tighten screw joint (pos. 20.17) gradually up to
tightness of the stuffing box packing (pos. 20.10).
ATTENTION !
Refer to item 10.0 and 11.0 before dismantling the valve.
ATTENTION at DN125-150!
- Ensure that the torsion lock is correctly
positioned when inserting new stem/
bellows unit. Introduce the grooved pin
(pos. 20.9) into the torsion lock groove.
Make sure it runs smoothly!
Fig. 14: Series 460
DN15-150