Gorman-Rupp Pumps PA6B60-6068H 1421583 and up - Manual (Page 42)

PA SERIES OM−06250
MAINTENANCE & REPAIR PAGE E − 20
Inspect the impeller and replace it if cracked or
badly worn.
For maximum pump efficiency, the impeller should
be centered within the volute scroll.
To verify the impeller positioning, measure the
pump casing and impeller as shown in Figure 10.
Use these measurements to calculate the required
impeller location (dimension E). Add or remove im-
peller adjusting shims until dimension E is ob-
tained.
D
B
2
A B
2
C D
E
Step 2 Step 1 Step 3
A+
B
2
C+
D
2
E = −
Figure 10. Centering Impeller Within Volute Scroll
Install the calculated thickness of impeller shims
(4). Install the impeller key (44) and slide the impel-
ler onto the shaft until fully seated. Make sure the
seal spring seats squarely over the step on the
back of the impeller.
Secure the shaft from rotating by reaching through
the discharge port and tightly wedging a soft-metal
bar between the vanes of the impeller. Install the O-
ring (41) in the groove in the impeller nut (42) and
secure the impeller with the impeller nut and fillister
head screw (40).
NOTE
After the impeller has been properly positioned,
check for free rotation. Correct any scraping bind-
ing before further reassembly.
Suction Head Installation
(Figure 4)
If removed at disassembly, press the wear ring (39)
into the suction head (38) until it seats squarely
against the bore shoulder.
The wear ring must seat squarely in the
suction head; otherwise binding and/or ex-
cessive wear will result.
Install the suction head gasket (37) on the casing
studs (33) and secure the suction head to the
pump casing with the nuts (34). Make sure the
jacking screws (43) do not interfere with the suc-
tion head seating.
Discharge Check Valve Assembly 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 (9) to hold it in place and po-