ARI Armaturen STEVI 471 EN - Manual (Page 9)

Rev. 0040305000 0410 Page 9
Operating and installation instructions
Straight through control valves - STEVI
®
470 / 471
7.1.2 Stuffing box packing design
The stuffing box packing (pos. 26) requires maintenance.
If leaks develop, immediately tighten the hexagon nuts (pos. 21) gradually until the packing
(pos. 26) stops leaking.
The service life of stuffing box packings (pos. 26) can be increased by checking regularly
leakage.
If leaks can no longer be stopped by tightening the nuts (pos. 21), a new packing ring
(pos. 26) must be inserted into the gland.
Replacement of stuffing box packing:
- Remove actuator. (Refer to operating instructions for actuator!)
- Insert the new packing ring (pos. 26) as shown in Fig. 11 and Fig. 12.
Damaged stems must also be replaced (refer to item 7.2 for instructions) since a new ring
pack will soon start leaking again if the stem is damaged.
ATTENTION !
Refer to item 10.0 and 11.0 before dismantling the valve.
Fig. 11: Stuffing box packing DN15-150 Fig. 12: Stuffing box packing DN125v-150v
Fig. 13: Split packing ring
If a split packing ring is used, cut with a chamfer
as shown in Fig. 13.