Hale Q Series Muscle - Manual (Page 125)

125 MUSCLE (Midship) Pumps Installation, Operation, and Maintenance Manual
p/n: 029-0020-63-0
Repair and Corrective Maintenance 
Figure 7-8: Clearance Ring and Impeller ID / OD Measurement
Inspect the front and back of both clearance ring IDs and ODs in several places for
signs of wear. Using a caliper, measure the inside diameter of each ring in several
places.
When new, the radial clearance between the impeller hub and the clearance rings is
between 0.005” to 0.007” (0.127-0.177mm) per side. Maximum acceptable radial
clearance on used pumps is between 0.015” to 0.020” (0.381-0.508mm) per side.
If the gap between the impeller and the clearance ring is greater than 0.020” (0.508
mm) you must measure the impeller hub diameter. (See Figure 7-8: “Clearance Ring
and Impeller ID / OD Measurement.”) If the impeller diameter is greater than 8.480”
(215 mm), the clearance ring must be replaced.
If the impeller diameter is less than 8.480” (215 mm) but more than 8.437”
(214 mm), the impeller hub diameter can be cut (turned down) and “undersized” clear-
ance rings can be ordered to compensate for the new impeller diameter. Contact Cus-
tomer Service at Hale Products at 610-825-6300.
CAUTION!
WHEN TURNING IMPELLERS TO FIT UNDERSIZED RINGS, CAUTION MUST BE EXER-
CISED TO ENSURE THAT THE CLEARANCE RING SURFACE RUNS TRUE WITH THE
BORE TO WITHIN 0.002” (0.051 MM).
If the impeller diameter is less than 8.437” (214 mm) and you are not meeting pump
performance, you may need to replace both the clearance rings and the impeller.