22.10.2002
GB
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Drive the cover out of the pump head by means of the punch, pos. E, which is inserted in the socket. Re-
move the pump head cover.
Impeller
The impeller (wear ring, pos. 49c) must fit into the neck ring, pos. 45. If the tolerance (clearance) between
neck ring and impeller (wear ring) is too big, replace the worn part.
The wear ring, pos. 49c, can be loosened from the impeller with light blows. Remove the ring.
Take care not to damage the impeller.
Neck ring
Free the neck ring, pos. 45, by pushing up the neck ring retainer, pos. 65, with the puller, pos. D.
Base
Push the inlet part, pos. 44, and the guide plate, pos. 6d, free of the base, pos. 6, using two screwdrivers.
Remove the gasket, pos. 37, from the base.
Outer sleeve
CRN 16 S: Remove the retaining rings, pos. 126 and 133, and the clamping plates, pos. 125 and 132.
5.2 Assembly
Before assembly, clean and check all parts.
Parts which are defective or do not comply with the measurements mentioned below due to wear should be
replaced by new parts.
Nut for shaft, gaskets and O-rings should always be replaced when the pump is overhauled.
Bearing
The maximum permissible difference between the diameters of the rotating bearing ring, pos. 47a, and the
stationary bearing ring in the chamber, pos. 4a, is 0.4 mm.
Pump head
Moisten the O-rings, pos. 78 and 98, with water and fit them to the collar and the socket of the pump head
cover, pos. 77.
Push the pump head cover into the pump head.
Make sure that the pump head cover is pressed home in the pump head.
Fit the O-ring, pos. 100, to the air vent screw, pos. 18, and fit the screw (right-hand thread) into the socket
of the pump head cover.
Moisten the recess of the pump head cover and the stationary shaft seal part with water.
Press the stationary shaft seal part into the recess of the pump head using fingers only, see section
4. Shaft
seals
.
The stationary seal ring must not be exposed to blows or knocks.
Moisten the gasket, pos. 37, with water and place it in the recess of the pump head.
Impeller
Press the wear ring, pos. 49c, carefully down over the impeller skirt.
Make sure to push the ring straight down and home against the impeller skirt and take care not to damage
the impeller.
Neck ring
Place the neck ring, pos. 45, on the chamber/inlet part. Then place the neck ring retainer, pos. 65, on the
neck ring and press it until it engages with the chamber/inlet part.
It must be possible to move the neck ring freely (sideways) between the retainer and the chamber/inlet part.
Note: No neck ring is fitted in the chamber, pos. 3a.
