5
Revised – June 2016
Impeller Shimming Procedure:
WARNING: This unit may be difficult to shim. Extreme care may be exercised.
Tools Needed: Machinist’s Parallel Bar
Vernier Caliper with depth measuring capability
Feeler gauges or depth gauge
Measure the Following:
Distance from the flange face to the housing (A)
Distance from the flange face to the motor shaft shoulder (B)
Impeller Thickness (C)
Measurements (A) and (B) are made by laying the parallel bar across the housing flange face and
measuring to the proper points. Each measurement should be made at three points, and the average
of the readings should be used.
Shim Thickness = B – (A+C)/2
After the impeller installation (step #4 above) the impeller/cover clearance can be checked with feeler
gauges, laying the parallel bar across the housing flange face. This clearance should nominally be
(A-C)/2.
C
B
A