Tilting Disc Type Check Valves
Date:
prepared:
approved:
Page:
22.03.2005
C.Wied
H.Six
13 of 14
Operating instruction No.:
BUW-510/1-E
11.3.7. Put on the end plate (20.1) and mount the keys (20.3) and lever (20.9).
Important
Do not use force to mount the end plate or the lever on the valve shaft! The
assembly should take place smoothly.
11.3.8. First tighten the packing nuts (18) equally.
11.3.9. Open and close the disc repeatedly. Check the packing nuts (18) and tighten them slightly
if necessary.
11.3.10. Pressurise the pipeline.
11.3.11. If the packing still leaks, tighten the packing nuts slowly and evenly until the leakage is
stopped. (See also Section 9 “Leakage at the shaft sealing”)
Important
Do not tighten the packing nuts (18) excessively. Otherwise the activation torque
will be increased to an impermissible level and the valve will be rough-running.
11.4. Replacing the lamellar sealing (Nos. 10)
11.4.1. Deinstall the butterfly valve from the pipeline with the disc closed. Clean the armature in
accordance with the equipment instructions or in another suitable way.
11.4.2. Open the valve disc (2) a few degrees, loosen the retaining ring screws (4) and open the
disc completely.
11.4.3. Mark the disc (2) and retaining ring (3) for correct reinstallation.
Note
For valves with low nominal width, it can be simpler to remove the drive and to turn
the disc out over the opening position in order to have more freedom of movement
for the remaining work.
11.4.4. Carefully remove the retaining ring screws (4) with the safety ring disc (5), then take off the
retaining ring (3).
11.4.5. Remove the lamellar sealing ring (10).
11.4.6. Check the seat in the housing, and if necessary clean it with solvent and fine emery cloth
(No. 600 or finer).
11.4.7. Check and clean the groove for the lamellar sealing. These area must be absolutely free of
all constituents before reassembly.
11.4.8. Insert new lamellar sealing (10) into the appropriate groove in the disc. Do not use any
force and do not damage the sealing.
11.4.9. Install the retaining ring (3) taking note of the markings (see section 11.4.3).
11.4.10. Clean the retaining ring screws (4) thoroughly and lubricate the thread with Molykote Plus
or equivalent. Insert the retaining ring screws (4) with the associated safety discs (5) and
tighten by hand.
11.4.11. Turn the valve disc in and then out twice in the seat.