ARI Armaturen STEVI 460 DN 15-250 EN - Manual (Page 9)

Rev. 0040304000 0410 Page 9
Operating and installation instructions
Straight thr. stop valves - STEVI
®
405 / 460 (DN15-250)
7.0 Care and maintenance
Maintenance and maintenance intervals have to be defined by the operator according to
the service conditions.
7.1 Replacement of stem sealings
7.1.1 PTFE V-ring unit design
PTFE V-ring unit (pos. 12) consisting of: 1 backing ring
4 sealing rings
1 cover ring
Owing to the installed compression spring (pos. 15), this stem packing is self-adjusting. If
the stem starts leaking, the ring pack is worn out and must be replaced.
Replacement PTFE V-ring unit:
- Remove actuator. (Refer to operating instructions for actuator!)
- When replacing PTFE V-ring unit (pos. 12), make sure that the parts are installed in the
correct order and positions (refer to Fig. 8 - Fig. 9).
- DN15-100: Gasket (pos. 17) must be replaced.
Damaged stems must also be replaced (refer to item 7.2 for instructions) since a new
sealing will soon start leaking again if the stem is damaged.
ATTENTION !
Refer to item 10.0 and 11.0 before dismantling the valve.
Fig. 8: PTFE V-ring unit DN15-100 Fig. 9: PTFE V-ring unit DN125-150