54
Make sure ring fits on impeller are free of nicks or burrs. Heat new ring to 225 degrees F (107°C)
and install on impeller. Drill and tap new holes in impeller, located from clearance holes in ring for
No. 10-24 x ½" setscrews spaced half the circular distance from the previously used holes in the
impeller. See sketch below.
TYPICAL SCREW INSTALLATION FOR IMPELLER RINGS
NOTE
Impeller wear rings when installed must be machined to establish original diameter and running
clearance.
NOTE
Whenever an impeller has new wear rings fitted it must be dynamically balanced before being
reassembled.
7.3
Case Wear Ring (and Casing Cover Wear Ring When Fitted)
Each wear ring is locked against rotation with a cylindrical pin.
To remove the wear ring, press it out. If this method does not easily effect removal of the ring, it
can be split apart. First, however, drill one or more holes in the face of the worn ring.
New rings to be installed must be shrunk by freezing when installing in casing or casing cover. Fit
and secure with a locking pin.
Replacement wear rings are furnished standard size in the bore.
