Checking The Gap Between The Impeller And The Pump Housing/Cover (Wear Rings) - Grundfos NK Service Instructions Manual

29. Assemble the lock ring, cover and V-ring.
Use locally approved lubricants (example: Rocol
sapphire aqua SIL).
30. Assemble the coupling guard retainer.
31. Tighten coupling guard retaining screws. See section
table.
20
5.2 Checking the gap between the impeller and the
pump housing/cover (wear rings)
1. Measure and note the diameter of the impeller and cover
interfaces.
Two measurements must be made (positions 12-6 and
3-9). The wear ring may be worn oval due to different
directions of radial forces.
6.1 Torque
2. Measure and note the diameter of the pump housing interface to
the impeller.