6-6. FIRE PUMP - Continued
(8) Place impeller and shaft assembly in an arbor press so
that impeller assembly (11) is adequately supported by
wear ring hub. Apply force to upper end of shaft (12) until
impeller (11) is free.
REMOVING IMPELLER ON
AN ARBOR PRESS
Inspection of Pump Body.
Check wear rings and impeller hubs for deep grooves or scratches. Position each wear ring on impeller
hub on which it was used, hold wear ring firmly against one side of hub, and measure total clearance on
opposite side (original factory clearance is from 0.007 to 0.014 in. (.178-.356 mm). If clearance is
excessive, turn the impeller hubs, and install undersize wear rings as directed below in table A.
If replacing the impeller is necessary, be sure to install new, standard size wear rings. Examine snap
rings, lock nuts, washers, and keys for corrosion and other damage, and replace if condition is doubtful.
These parts seldom need replacing if handled properly during pump disassembly and reassembly. If the
total clearance between the stuffing box end and the impeller shaft is much greater than 0.011 in. (.279
mm), then replacing the stuffing box end may be desirable.