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Pump Maintenance

13. Reinstall the impeller as described in (2.) above and recheck run-
out.

12.10 Installing the back pull-out assembly

1. Clean the casing, fit and install the casing gasket on the back
cover.
2. Loosen the bolts and jacking screws on the thrust bearing cap.
3. Install the back pull-out assembly in the casing.

4. Install the casing bolts finger tight, then tighten them to the
torque value required by the manufacturer.
5. Install the casing jacking screws as a snug fit. Do not overtighten.
6. Ensure that the total travel of the impeller in the casing is within
the pump manufacturer's tolerances. Most ANSI pump designs
arc between 0.030 inches and 0.065 inches.

7. Tighten the thrust bearing cap bolts evenly, drawing the cap
towards the bearing housing, until the impeller just contacts the
casing.
8. Set the dial indicator so that the button contacts the end of the
shaft.

9. Set the dial indicator to zero and back off the bolts about one
turn.
10. Tighten the jacking screws evenly (about one flat at a time), thus
backing away the bearing cap from the beating housing until the
dial indicator shows the required clearance.
11. Evenly tighten the bolts and jacking screws, keeping the indicator
at the required setting.
12. Check the shaft to ensure it still turns freely.
Whenever possible, the same people who start any repair or upgrade on
a particular pump should see that job all the way through. This will
minimize a potential problem arising from miscommunication
regarding what has and what has not been done during the repair
procedure.

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