Gorman-Rupp Pumps S8A1-E95 575/3 1429751 and up - Manual (Page 38)

S SERIES PUMPS OM-06258
MAINTENANCE AND REPAIR PAGE E - 12
Be sure the impeller bore and the shaft are free of
oily film and completely dry. Do not apply lubri­
cants of any kind to the impeller bore or the tapered
section of the shaft. Install the impeller (2) and im­
peller washer (56) on the rotor shaft (23).
After the impeller is installed, coat the threads of
the rotor shaft with `Loctite Threadlocker No. 242'
or equivalent compound. Install the impeller nut
(57). Insert a 3/4 inch square X 36 inch (19 mm
square X 914 mm long) rod between the vanes of
the impeller and torque the impeller nut to 300 ft.
lbs. (3600 in. lbs.or 42 m. kg.).
Remove the rod and turn the impeller to check for
free rotation.
NOTE
If the impeller (2) is not fully seated and binds
against the diffuser, the shaft and lower bearing
have been driven out of position during impeller re­
moval. If this occurs, the lower bearing must be
pressed back into place. (See Motor Disassembly
and Motor Reassembly.)
Suction Head And Strainer Plate Installation
(Figure E-1)
Inspect and thoroughly clean the suction head (58)
and its O‐ring groove. It must be clean and free of
any flaws which could cut the O‐ring or prevent a
good seal. Lightly oil the O‐ring (5) and install it in
the suction head.
Clean the suction head spacers (6) and shims (7)
and install them on the studs (59) in the same order
and position as previously removed.
Position the suction head on the diffuser studs
(59). Using a soft faced mallet, “walk” the suction
head into the diffuser until fully seated. Be careful
not to damage the O‐ring (5). Secure the suction
head with nylon locknuts (60).
For maximum pump efficiency, there should be a
clearance of .010 to .015 inch (0,25 to 0,38 mm) be­
tween the suction head and the face of the impeller.
Use a feeler gauge to measure this clearance. If the
clearance is not within the specific limits, remove
the suction head and add or remove adjusting
shims (7) as required. If necessary, the spacers (6)
may also be removed. Turn the impeller and check
for free rotation.
NOTE
If the intermediate and rotor subassembly (17 and
23) were not removed from the motor housing dur­
ing pump end disassembly, allowance must be
made for bearing play when checking impeller
clearance. Final impeller clearance must then be
determined with the pump in a normal upright op­
erating position.
Clean the gasket surface between the intermedi­
ate (17) and the strainer plate (12) to ensure that
the old gasket and gasket cement is removed. In­
spect the surface for major scratches. Secure the
strainer plate gasket (14) to the intermediate with a
light coating of `3M Gasket Adhesive No. 847' or
equivalent compound.
Position the strainer plate (12) over the diffuser,
aligning the bolt holes. Use a soft faced mallet to
tap the strainer plate into position, taking care not
to damage the diffuser O‐ring (8).
Apply `Never‐Seez' or equivalent compound to the
threads of the capscrews (10) and torque evenly in
a cross sequence to 120 ft. lbs. (1440 in. lbs. or
16,6 m. kg.).
Strainer Screen And Base Plate Installation
(Figure E-1)
Inspect the strainer screen (48) and base plate (53)
for cracks, distortion or erosion, and replace it if de­
fective.
Carefully position the strainer screen on the strain­
er plate (12) so that it seats against the strainer
plate shoulder. Install the base plate over the
screen, aligning the bolt holes. Secure the com­
plete strainer assembly using the hardware (50, 51
and 52). Make certain that the strainer seats prop­
erly against the shoulder of the strainer plate.
See FINAL ASSEMBLY and VACUUM TESTING
followed by LUBRICATION before putting the
pump back into service.