EBARA EFQT8 - Manual (Page 34)

EBARA Fluid Handling 33
Install the same thickness of impeller adjusting
shims as previously removed. Apply Never-Seez’
or equivalent to the shaft threads and screw the
impeller 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 1.02mm)
Between the impeller and the seal plate is
recommended for maximum pump efficiency.
Measure this clearance, and add or remove
impeller adjusting 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
before installing the impeller cap screw and washer
(19 and 20). The rotating assembly must be
installed in the pump casing in order to torque the
impeller capscrew.
After the rotating assembly is installed in the pump
casing, coat the threads of the impeller capscrew
(20) with ‘Never-Seez’ or equivalent compound,
and install the impeller washer (19) and capscrew;
torque the capscrew to 90 ft. lbs. (1080 in.lbs. or
12.4 m.kg.)
Rotating Assembly Installation
(Figure 2)
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.
Carefully wash all metallic parts in fresh cleaning
solvent and allow to dry thoroughly.
CAUTION!
Do not attempt to separate the rotating portion of
the seal from the shaft sleeve when reusing an old
seal. The rubber bellows will adhere to the sleeve
during use, and attempting to separate them could
damage the bellows.
Inspect the seal components for wear, scoring,
grooves, and other damage that might cause
leakage. Inspect the integral shaft sleeve for nicks
or cuts on either end. If any components are worn,
or the sleeve is damaged, replace the complete
seal; never mix old and new seal parts.
Install the stationary seal element in the stationary
seat. Press this stationary subassembly into the
seal plate bore until it seats squarely against the
bore shoulder. A push tube made from a piece of
plastic pipe would aid this installation. The I.D. of
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
Adjustment.
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.
CAUTION!
The shaft and impeller threads must be completely
clean before reinstalling the impeller. 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 impeller or shaft.