Gorman-Rupp Pumps 12B65-B 776101 and up - Manual (Page 33)

10 SERIES OM-02149
MAINTENANCE & REPAIR PAGE E - 10
Pump Casing Installation
Remove the hardware temporarily securing the
seal plate to the pedestal. Install the same thick­
ness of pump casing gaskets (36) as previously re­
moved and secure the pump casing (1) to the seal
plate (35) and pedestal (25) with the nuts (34). 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 (38) is also
recommended for maximum pump efficiency. Set
this clearance by adding or removing gaskets in
the pump casing gasket set (36) until the impeller
scrapes against the wear plate when the shaft is
turned by hand. After the impeller scrapes, add ap­
proximately .008 inch (0,20 mm) of gaskets.
After the face clearance has been set, tighten the
nuts (34) securing the pump casing to the pedes­
tal.
Back Cover Installation
If the wear plate (38) was removed for replace­
ment, secure it to the cover plate (43) using the at­
taching hardware (39 and 40) at this time. The wear
plate must be concentric to prevent binding when
the back cover is installed.
Clean any scale 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 (41) 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 (48) and tightening the clamp bar screw
(47). 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
(53 and 57) and check valve gasket (56) using the
attaching hardware (54 and 55).
Position the check valve assembly (52) on the tabs
on the check valve seat (49) with the large weight
toward the inside of the pump casing. Install the in­
ner check valve gasket (60) on the studs (50).
Position the check valve assembly and seat in the
suction port. Install the outer check valve gasket
(59) and suction flange (58). Secure the complete
assembly with the nuts (51). Check the operation
of the check valve to ensure proper seating and
free movement.
Final Pump Assembly
Secure the pump to the base with the previously re­
moved hardware. Connect the power source. Be
sure to reinstall any leveling shims used under the
pump mounting feet.
Be sure the pump and power source 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. Open all the
valves in the suction and discharge lines.
Be sure the pump and power source 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.