MR−05861
PA SERIES PUMPS
MAINTENANCE & REPAIR
PAGE C − 17
Lubricate the seal as indicated in
LUBRICATION
,
after the impeller has been installed.
Impeller Installation And Adjustment
(Figure C−2)
Inspect the impeller assembly (2) and replace it if
cracked or badly worn. The impeller assembly
consists of the impeller with a spring retainer (2A)
pressed onto the back side. If the retainer requires
replacement, use a puller to remove the old one.
Press the new retainer onto the impeller with the
step toward the seal side of the impeller.
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.
Install the same thickness of impeller adjusting
shims (5) as previously removed and screw the im-
peller assembly onto the shaft until tight.
Make
sure
the seal spring seats squarely over the step
on the spring retainer.
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 C−2)
If the wear plate (28) was removed, position the re-
placement wear plate in the pump casing and se-
cure it with the hardware (29 and 30).
Remove the two capscrews temporarily holding
the seal plate and install the same thickness of cas-
ing gaskets (6) as previously removed. Secure the
seal plate and pump casing to the intermediate
with the nuts (8).
Do not
fully tighten the nuts until
the impeller face clearance has been set.
A clearance of .010 to .020 inch (0,25 to 0,51 mm)
between the impeller and the wear plate is also rec-
ommended for maximum pump efficiency. This
clearance may be determined by reaching through
the suction inlet and measuring the clearance with
a feeler gauge. Add or remove gaskets in the pump
casing gasket set until the proper clearance is
achieved.
Reinstall any leveling shims used under the casing
mounting feet and secure the casing to the base
with the previously removed hardware.
Connect the hose (38) to the connector (37) and
secure it with the hose clamp (39). Secure the
bottle oiler (35) and bracket (36) to the back of the
intermediate with the previously removed hard-
ware.
(Figure C−1)
Apply a small amount of light grease to the gasket
(8) to hold it in place and position it against the
pump casing flange. Position the discharge check
valve assembly (5) and secure it with the hardware
(6, 7 and 9).
NOTE
When facing the discharge flange, install the stud
(9) in the hole at the 11 o’clock position.
Discharge Check Valve Assembly And
Installation
(Figure C−1)
The flapper and gasket are the only serviceable
parts of the check valve. If the flapper requires re-
placement, remove the hardware securing the
cover and gasket. Separate the valve cap and re-
place the flapper.
Install the valve cap gasket and secure the cap with
the previously removed hardware.
Support the discharge check valve assembly (5)
using a sling and a suitable lifting device. Using the
