Gorman-Rupp Pumps U3A60S-B 1289513 and up - Manual (Page 36)

OM-05662 SUPER U SERIES
MAINTENANCE & REPAIR PAGE E - 13
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
(Figure 2)
Inspect the impeller, and replace it if cracked or
badly worn. Inspect the impeller and shaft threads
for dirt or damage, and clean or dress the threads
as required.
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 as previously removed. Apply `Never‐Seez'
or equivalent to the shaft threads and screw the im­
peller onto the shaft until tight. Be sure the seal
spring seats squarely over the shoulder on the
back side of the impeller.
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 recom­
mended for maximum pump efficiency. Measure
this clearance, and add or remove impeller adjust­
ing shims as required.
NOTE
If the rotating assembly has been installed in the
pump casing, this clearance may be measured by
reaching through the priming port with a feeler
gauge.
Proceed with Rotating Assembly Installation be­
fore installing the impeller capscrew and washer
(27 and 28). The rotating assembly must be in­
stalled in the pump casing in order to torque the im­
peller capscrew.
After the rotating assembly is installed in the pump
casing, coat the threads of the impeller capscrew
(28) with `Never‐Seez' or equivalent compound,
and install the impeller washer (27) and capscrew;
torque the capscrew to 90 ft. lbs. (1080 in. lbs. or
12,4 m. kg.).
Rotating Assembly Installation
(Figure 1)
Install the seal plate and bearing housing O‐rings
(7 and 8) and lubricate them with light grease. Ease
the rotating assembly into the pump casing using
the installation tool. Be careful not to damage the
O‐ring.
Install the same thickness of rotating assembly ad­
justing shims (6) as previously removed, and se­
cure the rotating assembly to the pump casing with
the hardware (4 and 5).
To set the impeller and wear plate clearance, refer
to Suction Back Cover Installation And Adjust­
ment.
Suction Back Cover Installation And
Adjustment
(Figures 1 and 5)
If the wear plate (9) was removed for replacement,
carefully center it on the suction back cover and se­
cure it with the hardware (11 and 12). The wear
plate must be concentric to prevent binding when
the back cover is installed.
Clearance between the impeller and wear plate is
adjusted using four adjusting screws and locking
collars. 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 .003 to .010 inch (0,07 to 0,25
mm).
Replace the suction back cover and wear plate O‐
rings (10 and 13) and lubricate them with a gener­