Gorman-Rupp Pumps 81 1/2A2-B 253703 and up - Manual (Page 30)

OM−00740 80 SERIES
MAINTENANCE & REPAIR PAGE E − 9
Slide the seal plate assembly over the impeller
shaft (17) and temporarily secure the seal plate to
the pedestal (14) using two capscrews and nuts
(3/8−16 UNC x 1−1/2 inch long, not supplied).
Slide the inboard rotating element into the lubri-
cated seal liner with the chamfered side toward the
shaft sholder.
Subassemble the inboard stationary seat, packing
ring and stationary washer. Press this unit into the
lubricated seal liner until the seal faces contact. A
push tube cut from a length of plastic pipe would
aid this installation. The I.D. of the tube should be
approximately the same size as the I.D. of the seal
spring.
Slide the spacer sleeve onto the shaft until it seats
against the inboard rotating element and install the
seal spring.
Subassemble the outboard stationary seat, pack-
ing ring and stationary washer. Press this unit into
the lubricated seal liner. Install the outboard rotat-
ing element with the chamfered side toward the
impeller.
Lubricate the seal assembly as indicated in LU-
BRICATION after the impeller has been installed.
Impeller Installation
Inspect the impeller 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 shims (10) as
previously removed and screw the impeller onto
the shaft until tight.
Make sure the seal spring seats
squarely over the step on the back of the impeller.
The clearance between the back of the impeller
and the seal plate should be between 0.015 and
0.025 inch (0,38 to 0,63 mm). Measure this clear-
ance and add or remove shims from the impeller
adjusting shim set (10) until the correct clearance
is achieved.
Pump Casing and Wear Plate Installation
If the wear plate assembly (25) was removed,
install the new wear plate in the pump casing and
secure it with the hardware (39 and 40). Be sure to
install new fiber washer (27) and do not over-tight-
en the capscrew (28). Over-tightening the caps-
crew can crush the fiber washer, resulting in leak-
age.
Remove the two capscrews temporarily securing
the seal plate to the pedestal. Install a new set of
casing gaskets (24) and slide the pump casing
over the impeller and against the gaskets. The
clearance between the face of the impeller and the
wear plate should be between .008 and .015 inch
(0,20 to 0,38 mm). Remove gaskets from the gas-
ket set until the correct clearance is achieved. Se-
cure the pump casing to the seal plate and pedes-
tal with the nuts (22).
Suction Check Valve Installation
If the check valve assembly (29) was disas-
sembled, use the hardware (30 and 31) to secure
the weights (32 and 34) to the new gasket (33).
Position the check valve assembly over the studs
with the large weight toward the inside of the
pump. Secure the suction flange (37) and check
valve assembly to the pump casing with the nuts
(36).
Check the operation of the check valve to ensure
proper seating and free movement.
Final Pump Reassembly
Be sure all hardware and drain plugs are tight, and
that the pump is secure to the base and power
source.
Install the suction and discharge lines and open all
valves. Make certain that all piping connections are
tight, and that the weight of the lines is indepen-
dently supported and secure.
Before starting the pump, fill the pump casing with
clean liquid. Apply Never-Seez" or equivalent