Gorman-Rupp Pumps PA4A60-4024T 1476457 and up - Manual (Page 45)

OM−06415 PA SERIES
MAINTENANCE & REPAIR PAGE E − 23
the pipe should be slightly larger than the O.D. of
the shaft sleeve.
Slide the rotating portion of the seal (consisting of
the integral shaft sleeve, spring centering washer,
spring, bellows and retainer, and rotating element)
onto the shaft until the seal faces contact.
Proceed with Impeller Installation and Adjust-
ment.
Impeller Installation And Adjustment
(Figure 5)
Inspect the impeller (1) and replace it if cracked or
badly worn.
The shaft and impeller threads must be
completely clean before reinstalling the im-
peller. Even the slightest amount of dirt on
the threads can cause the impeller to seize
to the shaft, making future removal difficult
or impossible without damage to the im-
peller or shaft.
Apply a small amount of ‘Never-Seez’ or equivalent
anti-lock compound on the shaft threads. Screw
the impeller onto the shaft until tight.
NOTE
At the slightest sign of binding, immediately back
the impeller off, and check the threads for dirt. Do
not try to force the impeller onto the shaft.
A clearance of .025 to .040 inch (0,64 to 1,02 mm)
between the impeller and the seal plate is neces-
sary for maximum pump efficiency. Measure this
clearance, and add or remove impeller adjusting
shims as required.
Pump Casing And Wear Plate Installation
(Figure 4)
If the wear plate (2) was removed, position the re-
placement wear plate in the casing and secure it
with the hardware (11 and 12).
Lubricate the O-rings (3 and 4) with light grease,
and install them in the grooves in the bearing hous-
ing and seal plate. Use a suitable lifting device to
position the pump casing over the rotating assem-
bly. Be careful not to damage the O-rings.
Install the same thickness of adjusting shims (8) as
previously removed, and secure the rotating as-
sembly to the pump casing with the hardware (6
and 7). Do not fully tighten the capscrews until the
impeller face clearance has been set.
A clearance of .010 to .020 inch (0,25 to 0,5 mm)
between the impeller and the wear plate is also rec-
ommended for maximum pump efficiency. This
clearance can be obtained by adding or removing
an equal thickness of shims from each rotating as-
sembly shim sets (8) until the impeller scrapes
against the wear plate when the shaft is turned. Af-
ter the impeller scrapes, add approximately .010
inch (0,25 mm) of shims to each shim set.
After the face clearance has been set, tighten the
hardware securing the rotating assembly to the
pump casing.
Reinstall any leveling shims used under the pump
casing mounting feet and secure the casing (1) to
the base with the previously removed hardware.
Discharge Check Valve Reassembly And
Installation
(Figure 3)
If the discharge check valve (7) was disassembled
to replace the flapper or cover O-ring, position the
flapper in the valve body and check to ensure free
movement.
Install the valve cover O-ring and secure the cover
to the body with the previously removed hardware.
Apply a small amount of light grease to the dis-
charge flange gasket to hold it in place and posi-
tion it against the pump casing flange. Support the
discharge check valve assembly using a sling and
a suitable lifting device. Using the previously re-
moved hardware, secure the discharge check
valve assembly and flange gasket to the pump as-
sembly (1).
Priming Chamber Assembly And Installation
(Figure 7)
Clean and inspect the components of the priming
valve (1). Inspect the linkage and ensure the orifice