Gorman-Rupp Pumps 16A22-B 1068713 and up - Manual (Page 30)

10 SERIES OM−00711−04
MAINTENANCE & REPAIR PAGE E − 10
Impeller Installation And Adjustment
Inspect the impeller, and replace it if cracked or
badly worn. Install the same thickness of impeller
shims (74) as previously removed. Apply ‘Never-
Seez’ or equivalent compound to the shaft threads
and screw the impeller onto the shaft until tight.
A clearance of .020 to .040 inch (0,51 to 1,02 mm)
between the impeller and the seal plate is neces-
sary for maximum pump efficiency. Measure this
clearance and add or remove impeller shims until
this clearance is reached.
NOTE
Be sure the seal plate is tight against the pedestal
while measuring this clearance.
Apply a thin coat of ‘Never-Seez’ or equivalent
compound to the threads on the socket head caps-
crew (50) and install the capscrew and impeller
washer (49). Torque the impeller capscrew to 90 ft.
lbs. (1080 in. lbs. or 12,4 m. kg.)
Pump Casing Installation
Remove the hardware temporarily securing the
seal plate to the pedestal. Install the same thick-
ness of pump casing gaskets (11) as previously re-
moved. Using a suitable hoist and sling, secure
the pump casing (1) to the seal plate (12) and ped-
estal (23) with the nuts (45). Do not fully tighten the
nuts at this time.
NOTE
It is recommended that the back cover be installed
now. The back cover assembly must be in place to
adjust the impeller face clearance.
A clearance of .008 to .015 inch (0,20 to 0,38 mm)
between the impeller and the wear plate (47) is also
recommended for maximum pump efficiency. Set
this clearance by adding or removing gaskets in
the pump casing gasket set (11) until the impeller
scrapes against the wear plate when the shaft is
turned. After the impeller scrapes, add approxi-
mately .008 inch (0,20 mm) of gaskets.
After the face clearance has been set, tighten the
nuts (45) securing the pump casing to the pedes-
tal.
Back Cover Installation
If the wear plate (47) was removed for replace-
ment, secure it to the cover plate (53) using the at-
taching hardware (57 and 58). The wear plate must
be concentric to prevent binding when the back
cover is installed.
Clean any scales or debris from the contacting sur-
faces on the pump casing that might prevent a
good seal with the back cover. Replace the back
cover gasket (51) and slide the back cover assem-
bly (52) into the pump casing. Be sure the wear
plate does not scrape against the impeller.
NOTE
To ease future disassembly, apply a film of grease
or ‘Never-Seez’ on the back cover shoulder, or any
surface that contacts the pump casing. This action
will reduce rust and scale build-up.
Secure the back cover assembly by installing the
clamp bar (60) and tightening the clamp bar screw
(59). Do not over-tighten the clamp bar screw; it
should be just tight enough to seal the back cover
shoulder.
Suction Check Valve Installation
Inspect the check valve components and replace
as required. Subassemble the check valve weights
(71 and 73) and check valve gasket (72) using the
attaching hardware (69 and 70).
Position the check valve assembly (68) in the
check valve seat (62) with the large weight toward
the inside of the pump casing. Install the check
valve seat gasket (61) and secure the valve seat to
the suction port with the machine screws (67).
NOTE
To ease future disassembly, apply a film of grease in
the valve seat slot for the check valve. This action
will help reduce rust and seizing.
Replace the suction flange gasket (63) and secure
the suction flange (64) with the nuts (66). Check