ARI Armaturen STEVI 451 EN - Manual (Page 10)

Page 10 Rev. 0040306000 0410
Operating and installation instructions
3-way control valves - STEVI
®
450 / 451
7.1.2 Stuffing box packing design
The stuffing box packing requires maintenance.
If leaks develop, immediately tighten the screw joint (pos. 42) respectively the hexagon nuts
(pos. 24) gradually until the packing ring (pos. 13) stops leaking.
The service life of stuffing box packings (pos. 13) can be increased by checking regularly
leakage.
If leaks can no longer be stopped by tightening the screw joint (pos. 42) respectively the
nuts (pos. 24), a new packing ring (pos. 13) must be inserted into the gland.
Replacement of stuffing box packings:
- Remove actuator. (Refer to operating instructions for actuator!)
- Insert new packing ring as shown in the Fig. 13 and Fig. 14.
Damaged stems must also be replaced (refer to point 7.2 for instructions), since a new
sealing will soon start leaking again if the stem is damaged.
ATTENION !
Refer to point 10.0 and 11.0 before dismantling the valve.
Fig. 13: Stuffing box packing DN15-150 Fig. 14: Stuffing box packing DN125v-150v
Fig. 15: Split packing ring
If a split packing ring is used, cut with a chamfer
as shown in
Fig. 15.