Gorman-Rupp Pumps 11 1/2A3-E2 1P 1045642 and up - Manual (Page 27)

OM-04091 10 SERIES
MAINTENANCE & REPAIR PAGE E - 7
Impeller Installation And Adjustment
Inspect the impeller, and replace it if cracked or
badly worn. Install the same thickness of impeller
shims (12) as previously removed, and screw the
impeller onto the shaft until tight.
A clearance of .010 to .012 inch (0,25 to 0,30 mm)
between the impeller and the intermediate is nec­
essary for maximum pump efficiency. Measure this
clearance and add or remove impeller shims until
this clearance is reached.
Pump Casing Installation
Install the same thickness of pump casing gaskets
(23) as previously removed, and secure the pump
casing to the intermediate (22) with the nuts (14).
Do not fully tighten the nuts at this time.
NOTE
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 is also rec­
ommended for maximum pump efficiency. Set this
clearance by adding or removing gaskets in the
pump casing gasket set (23) until the impeller
scrapes against the wear plate when the shaft is
turned. After the impeller binds, add approximately
.008 inch (0,20 mm) of gaskets.
After the face clearance has been set, tighten the
nuts (14) securing the pump casing to the interme­
diate.
Secure the pump casing to the base with the pre­
viously removed hardware. Be sure to reinstall any
leveling shims used under the casing mounting
feet.
Back Cover Installation
If the wear plate (24) was removed for replace­
ment, secure it to the cover plate (27) using the at­
taching hardware (31 and 32) at this time. 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 (26) and slide the back cover assem­
bly into the pump casing. Be sure the wear plate
does not bind 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 (30) and tightening the clamp bar screw
(29). 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
(35 and 38) and check valve (34) using the attach­
ing hardware (36 and 37).
Position the check valve assembly (33) in the suc­
tion port with the large weight toward the inside of
the pump casing. Install the suction flange (4), and
secure with the nuts (40). Check the operation of
the check valve to ensure proper seating and free
movement.
Final Pump Assembly
Be sure the pump and motor are securely
mounted to the base.
Install the suction and discharge lines and open all
valves. Make certain that all piping connections are
tight, properly supported and secure.
Be sure the pump and motor have been properly
lubricated, see LUBRICATION.
Remove the fill plug assembly (6) and fill the pump
casing with clean liquid. Reinstall the fill plug and
tighten it.
Refer to OPERATION, Section C, before putting
the pump back into service.