Pioneer PB Series, Operation & Maintenance Manual

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19
IMPELLER
The shaft and impeller threads must be completely clean
before re-installing the impeller. Apply anti-seize
compound to the external shaft threads.
Do not use anti-
seize compounds on the lockscrew threads! Screw the
impeller onto the shaft until tight. A clearance of .025 to
.035 between the impeller and the seal plate is
recommended for optimum pump efficiency. Measure this
clearance between the impeller and the rotating assembly
with the rotating assembly sitting on the impeller with the
shaft oriented vertically. Add or remove impeller adjusting
shims as required to achieve the correct clearance. Apply
Loctite 2760

, or equivalent thread locking compound, to
impeller screw and install impeller washer and screw.
Torque the impeller screw to a minimum of 175 foot pounds, maximum of 235 foot pounds.
Tighten the impeller lock screw by hand, and do not use a pneumatic wrench to tighten the.
Do not allow the shaft to rotate while tightening the lockscrew
INSPECTION COVER AND WEAR PLATE
Re-grease o-ring when installing and use 2760 Loctite® (red), or equivalent, on the wear plate
studs. Installation is the reverse of removal.
ROTATING ASSEMBLY
Re-grease o-ring and install rotating assembly into volute. Installation is the reverse of removal.
Upon installation, the clearance between the suction cover and impeller needs to be verified.
After sliding the rotating assembly back into the volute, evenly tighten rotating element bearing
housing fasteners until impeller lightly contacts wear plate. Note: the shaft will not rotate.
Tighten bearing housing jack screws until .010” to .020” increase in clearance is achieved.
.010” to .020” is the desired clearance between the impeller and wear plate.
This can be determined by taking measurements of the gap between the pump casing and the
bearing housing when the impeller is making contact with the wear plate, then re-measure the
same gap until the above increase in clearance is achieved at each corner of the bearing
housing.
Rotate shaft, making sure there isn’t any impeller/wear plate contact or rubbing. Tighten the
jack screws at each corner of the bearing housing (not too tight), then tighten the jackscrew
lock nuts to maintain setting position. Rotate shaft to verify the shaft is free to rotate without
the impeller rubbing on the wear plate after adjustment. If the impeller continues to rub on the
wear plate, repeat adjustment procedure above until the shaft rotates freely.
PRESSURE RELIEF VALVE
The suction cover is equipped with a pressure relief valve to provide additional safety for the
pump and operator. Make sure the relief valve is set to 80 psi
DANGER!!!
It is recommended that the pressure relief valve assembly be replaced at each overhaul, or any
time the pump overheats and activates the valve. Periodically, the valve should be removed for
inspection and cleaning.