Gorman-Rupp Pumps 12D-1B20 1483730 and up - Manual (Page 27)

OM−06360 10 SERIES
MAINTENANCE & REPAIR PAGE E − 9
Subassemble the inboard stationary seat, packing
ring and seal washer. Press this unit into the lubri-
cated seal liner.
Install the spacer sleeve and seal spring.
Subassemble the outboard stationary seat, pack-
ing ring and seal washer. Press this unit into the lu-
bricated seal liner.
Install the outboard rotating element with the
chamfered side toward the impeller end of the
shaft.
Install the grease cup and the elbow (4 and 5) in the
intermediate.
After the impeller has been installed, lubricate the
seal as indicated in LUBRICATION, Section E.
Impeller Installation And Adjustment
(Figure 2)
Inspect the impeller (12) and replace it if cracked or
badly worn. Install the same thickness of impeller
shims (11) as previously removed and screw the
impeller onto the shaft until tight.
A clearance of .015 to .040 inch (0,38 to 1,02 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
(Figure 2)
Install the same thickness of pump casing gaskets
(13) as previously removed and secure the pump
casing (1) to the intermediate (8) with the nuts (9).
Do not fully tighten the nuts at this time.
A clearance of .010 to .020 inch (0,25 to 0,51 mm)
between the impeller and the wear plate is also rec-
ommended for maximum pump efficiency. This
clearance must be set after installing the back cov-
er by adding or removing pump casing gaskets un-
til the impeller scrapes against the wear plate when
the shaft is turned. After the impeller scrapes, add
approximately .010 inch (0,25 mm) of gaskets.
After the face clearance has been set, tighten the
nuts (9) securing the pump casing to the intermedi-
ate.
See Figure 1 and secure the pump casing to the
base (4) with the hardware (7, 8, 9 and 10). Be sure
to reinstall any leveling shims used under the
mounting feet of the pump casing.
Back Cover Installation
(Figure 2)
Inspect the wear plate (14) and replace it if badly
worn or grooved. Carefully center the wear plate on
the back cover (24) and secure it with the hardware
(21 and 22). The wear plate must be concentric to
prevent binding when the back cover is installed.
Clean any scale or debris from the back cover
shoulder and pump casing which might prevent a
good seal.
NOTE
Apply a film of ‘Never-Seez’ or equivalent com-
pound on the back cover shoulder or any surface
which contacts the pump casing to ease future dis-
assembly and to reduce rust and scale build up.
Replace the back cover gasket (28) and slide the
back cover assembly into the pump casing. Be
sure the wear plate does not bind against the
pump casing.
Install the washers (22). Secure the back cover as-
sembly by tightening the wing nuts (23) evenly. Do
not over tighten the wing nuts; they should be just
tight enough to ensure a good seal at the back cov-
er shoulder.
Suction Check Valve Installation
(Figure 2)
Inspect the check valve components and replace
as required. Assemble the check valve weights to
each side of the check valve and secure with the
previously removed hardware.
Position the check valve assembly (26) in the suc-
tion port with the large weight toward the impeller
and the small weight toward the suction flange. In-
stall the suction flange (25) and secure it with the