Valtek FlowTop General Service Valve FCD VLENIM8610A4 11/18
18
29. Finish packing follower tightening with a wrench (See
Table 7, Page 9).
30. Replace the pneumatic diaphragm or multi-turn actua-
tor and accessories (See page 19).
31. After reinstalling the control valve in the pipeline,
perform 3 full strokes and check the tightening of the
packing follower and bonnet bolting.
NOTICE
Do not over tighten the packing. Over
tightened packing may produce
higher friction and reduce product service life.
32. Log the maintenance interval and the work performed.
MegaStream noise reduction and CavStream
anti-cavitation trims:
Structurally, there is no difference between a seat retainer
and a MegaStream retainer; both are assembled and disas-
sembled identically. Follow instructions in Section 13.
Figure 13: MegaStream
CavStream should be treated the same as the plug assembly.
Follow same instructions as noted on pages 13 through 18.
Figure 14: CavStream
NOTICE
Care should be taken to observe any
wear on the CavStream plug head.
(104) clockwise and finger tighten.
(See Section 14: Required Torques, for plug and stem)
17. Install the new bonnet gasket (58).
18. Install a new profile ring (55) and seat ring (20).
19. Lower the seat retainer (30) into the body and place it
on the seat ring.
20. Install the new seat retainer gasket (56) and the new
bonnet gasket (58).
21. Lower the plug assembly (50) into the body and place
it into the seat ring.
22. Install and finger tighten the bonnet nuts (114) to the
bonnet bolts (108).
23. Install the new head gasket (58) and carefully lower
the head (40) onto the stem and bonnet.
24. Install and finger tighten the nuts (110) to the studs (106).
25. Install the packing box ring (93) and the new packing (88).
NOTICE
Install and push two packing rings
consecutively using the Tamping
Tool and pre-tighten it using the Compression Tool.
Repeat the procedure with remaining rings. Rotate
each ring 180° from the overlapping point. Make sure
each ring is clean. Dirty rings result in stem leakage.
(See Parts - Packing, Page 20)
26. Install the upper stem guide (87), Belleville springs
(138), and the packing follower (80). Tighten the
packing follower with your fingers clockwise until
resistance can be felt.
NOTICE
The Belleville springs (138) must be
stacked in series.
27. Tighten the bonnet nuts (114) in four steps - 30%,
60%, 100%, and all around 100% - using a crosswise
pattern (See Section 14: Torque Requirements).
28. Tighten the nuts (110) in four steps - 30%, 60%, 100%,
and all around 100% - using a crosswise pattern (See
Section 14: Torque Requirements).
NOTICE
Check the plug’s freedom of move-
ment by pushing / lifting it approxi-
mately ~10 mm (0.4 inch) between tightenings. Loosen
the bolted connection and start again if it proves difficult
to move the plug.
