Gorman-Rupp Pumps PA6C60C-F6L 1477478 and up - Manual (Page 46)

PA SERIES OM−05771
MAINTENANCE & REPAIR PAGE E − 24
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.
Install the same thickness of impeller adjusting
shims (28) as previously removed and 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.
Apply ‘Never-Seeze’ or equivalent compound to
the threads of the capscrew (21). Secure the impel-
ler to the shaft with the impeller washer (22) and
capscrew. Torque the impeller capscrew to 90 ft.
lbs. (12,4 m. kg.).
Pump Casing Installation
(Figure 4)
Lubricate the O-rings (6 and 16) with light grease,
and install them in the grooves in the bearing hous-
ing and seal plate. Use a suitable hoist and sling to
slide the pump casing (1) over the rotating assem-
bly.
Install the same thickness of adjusting shims (14)
as previously removed and secure the rotating as-
sembly to the pump casing with the hardware (12
and 13).
Wear Plate And Back Cover Plate Installation
And Adjustment
(Figures 4 and 12)
If the wear plate (5) was removed for replacement,
carefully center it on the back cover (17) and se-
cure it with the hardware (3 and 4).
Lubricate the O-rings (6 and 16) with light grease
and install them in the grooves in the wear plate
and back cover.
Clearance between the impeller and wear plate is
adjusted using four back cover nuts (21) and lock-
ing collars (18). There are 18 detents on the I.D. of
each locking collar. Indexing the collars one detent
on the adjusting screws represents approximately
.005 inch (0,13 mm) of wear plate clearance. The
recommended clearance between the wear plate
and the impeller is .010 to .020 inch (0,25 to 0,50
mm).
USE TWO
OPPOSING
BACK COVER
NUTS TO PRESS
BACK COVER
INTO PUMP
CASING USE TWO REMAINING
ADJUSTING SCREWS AND
LOCKING COLLARS TO SET
FACE CLEARANCE
TURN INDEX COLLARS
3 DETENTS COUNTER-
CLOCKWISE, THEN
TURN CLOCKWISE UN-
TIL SCREW HOLES
ALIGN
Figure 12. Installing and Adjusting Back Cover
Screw the four adjusting screws (19) into the
tapped holes in the back cover plate until they are
just flush with the machined surface on the back
side of the cover plate.