DeZURIK
3-20” BAW AWWA Butterfly Valves
August 2013
Page 15
D10386
Reassembling Valve
(Continued)
•
On sizes 18 and 20", align and center the flat on the shaft
with the tapped hole in the disc. Insert the pin (A4) into
the mating hole in the disc (A2) so that the flat on the pin
is centered on the flat on the shaft. Tap the pin firmly into
position with a hammer and punch until the hammer
bounces back when the pin is struck. Apply one bead of
Loctite 242 to the threads of the set screw (A10) and one
bead along half the depth of the threads in the tapped
hole above the pin. Tighten the set screw to 125±5 ft. lbs.
See Figure 5. Apply one bead of Loctite 242 to the
threads of set screw (A12) and one bead along half the
depth of the threads in the threaded hole near the bottom
of the disc (A2). Thread the set screw into the disc and
into the blind hole in the lower shaft (A11) and tighten to
13±2 ft. lbs. See Figure 6.
Figure 6—Lower Set Screw
Detail 18” & 20”
6.
Apply PTFE pipe sealant to the threads of plug (A16) and tighten the plug securely in the
threaded hole in the bottom of the body.
7.
If the valve has a packing gland, mount the gland (A25) with the two screws (A26) and
washers(A27). Tighten the screws evenly and finger-tight, plus 1/2 turn.
8.
Mount the actuator (and adapter, if included) to the valve.
Replacing Bearings
1.
To replace bearing, disassemble the valve as instructed in the "disassembling valve" section.
2.
Remove the bearings from the upper and lower journals in the valve body.
Note:
If PFTE or Darcon bearings are used, fabricate a sleeve the same size as the bearing OD; insert
the sleeve into the bearing, and push the bearing out of the journal.
3.
Thoroughly clean the journals before inserting new bearings.
4.
Form new bearings into cylindrical shape and insert bearings into the journals until they stop
against the rubber seat ring or are 1/8" away from the body opening.
Note:
For 3-8" valves, warm the bearing to 350°F (177°C) before forming into the cylindrical shape to
avoid crimping the bearing material.
5.
For
PFTE or Darcon
bearings, apply a layer of Loctite to the outside surface of bearing, then use
sleeve to push it into the journal until its stops against the body step.
6.
Reassemble the valve as described in the "reassembling valve" section.