Checking And Replacing Impellers/Wear Rings And Neck Rings - Grundfos MTR 15 Service Instructions Manual

13. Check that the gaps either side of the coupling halves are equal.
14. Tighten the screws to the torque stated, see
15. Check that the shaft rotates freely and noiselessly.
16. Place the adjusting fork on the inside of one of the coupling guards.
17. Fit the coupling guard pos. 7 and the screws pos. 7a.

4.4 Checking and replacing impellers/wear rings and neck rings

Impellers/wear rings
1. Check whether there is a noticeable groove in the impeller skirts (CR 10) or wear rings (CR 15 and 20)
caused by friction (use a finger nail).
2. If there is a groove, the impellers/wear rings must be replaced. The wear rings can be removed by means
of the puller for neck ring
Neck rings
The neck rings pos. 65 should always be replaced if the chamber stack has been dismantled.
1. Push the retainer for neck ring free of the chamber using the puller for neck ring
2. Remove the neck ring pos. 45.
3. Fit a new neck ring in the chamber.
4. Press the retainer for neck ring down on the neck ring and make it engage with the chamber. It must be
possible to move the neck ring freely (sideways) between the retainer and the chamber.
Bearing rings
1. Check whether there is a visible or noticeable edge on the rotating bearing rings (use a finger nail).
2. The bearing rings pos. 47a and the chambers with bearing ring pos. 4a must be replaced at the same time.
Fig. 6 Gaps between coupling halves
2. Torques and
pos. C.
Fig. 7 Correct fitting of neck ring
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lubricants, and remove the adjusting fork.
pos. C.