WIKA CPB3800 Betriebsanleitung Seite 36

7. Maintenance, cleaning and recalibration
7.2.4 Valve seals
1. Unscrew the gland nut.
GB 2. Unscrew the valve spindle and remove the bonded seal.
3. Slide gland nut off spindle.
4. Using a suitable hooked tool remove the O-ring seal (9) from the bore of the gland
nut. Renew O-ring and bonded seal (10).
5. On replacement ensure that O-ring is correctly located in the groove and all sealing
faces are clean. Remove all burrs from spindle.
7.2.5 Screw pump
1. Using a 4mm hexagon wrench key unscrew the six socket head cap screws secur-
ing the hub locating plate. (These are positioned inside the recess in the back of the
aluminium hub).
2. By carefully pulling the hub the complete ram assembly can now be withdrawn from
the barrel (During this operation a container is required beneath the barrel to catch
any liquid).
3. Unscrew the ram from the hub assembly.
4. The high pressure seal (12) and low pressure seal (15) can now be replaced. Before
fitting the new seals check the ram is not scored on the locating diameters.
5. At this point the hub assembly should be checked for excess play indicating wear in
the bearing and for wear in the screwed spindle and nut. If any wear is found it will be
necessary to dismantle the hub assembly.
6. Check the bore of the block assembly (11) is not badly scored or pitted. If a replace-
ment is required this item is supplied complete with valves. The block is attached to
the base by socket head cap screws.
7. Re-assembly is a straightforward reversal of the above procedures.
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On assembly care should be taken to align the ram to prevent bending,
or damage to the seals. Excessive force should not be used.
The socket head cap screws are not spaced equally around the locating
flanges so check hole alignment before inserting screws.
WIKA operating instructions model CPB3800