Gorman-Rupp Pumps T4A3-B /F,/FM - Manual (Page 36)

OM-01043 T SERIES
MAINTENANCE & REPAIR PAGE E - 13
the pipe should be slightly larger than the O.D. of
the shaft sleeve.
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 (29) as previously removed. Apply `Never‐
Seez' or equivalent to the shaft threads 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 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.
NOTE
Proceed with Rotating Assembly Installation be­
fore installing the impeller capscrew and washer
(22 and 23). 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
(23) with `Never‐Seez' or equivalent compound,
and install the impeller washer (22) and capscrew;
torque the capscrew to 90 ft. lbs. (1080 in. lbs. or
12,4 m. kg.).
Rotating Assembly Installation
(Figure 1)
NOTE
If the pump has been completely disassembled, it
is recommended that the suction check valve and
back cover assembly be reinstalled at this point.
The back cover assembly must be in place to adjust
the impeller face clearance.
Install the bearing housing O‐rings (8 and 12) and
lubricate it with light grease. Ease the rotating as­
sembly into the pump casing using the installation
tool. Be careful not to damage the O‐rings.
Install the four sets of rotating assembly adjusting
shims (11) using the same thickness as previously
removed. Secure the rotating assembly to the
pump casing with the hardware (9 and 10). Do not
fully tighten the capscrews until the back cover has
been reinstalled and 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 can be obtained by removing an equal
amount of shims from each rotating assembly
shim set until the impeller scrapes against the wear
plate when the shaft is turned. After the impeller
scrapes, add approximately .015 inch (0,4 mm) of
shims to each shim set.
NOTE
An alternate method of adjusting this clearance is to
reach through the suction port with a feeler gauge
and measure the gap. Add or subtract rotating as­
sembly shims accordingly.