Gorman-Rupp Pumps 112A20-B 814882 and up - Manual (Page 25)

OM−00701 10 SERIES
MAINTENANCE & REPAIR PAGE E − 5
removing the discharge piping. However, due to
the weight of the impeller and the tight fit through
the suction port, it is recommended that the dis-
charge piping be removed and the pump casing
(1) be separated from the pedestal to provide bet-
ter access.
Use lifting and moving equipment in
good repair and with adequate capacity
to prevent injuries to personnel or dam-
age to equipment. Suction and dis-
charge hoses and piping must be re-
moved from the pump before lifting.
Support the pump casing using a suitable hoist
and sling.
Remove the hardware (5) securing the pump cas-
ing to the pedestal. Pull the casing straight away
from the pedestal to prevent binding on the impel-
ler. Remove the pump casing gasket (35) and
clean the mating surfaces.
Impeller Removal
Before removing the impeller, remove the bottle oil-
er and piping (9, 10 and 11). Remove the pipe plug
(32) and drain the seal cavity. This will prevent oil
from escaping when the impeller is removed.
Clean and reinstall the pipe plug.
To loosen the impeller nut, the impeller shaft must
first be disconnected from the power source. With
the power source disengaged, install the key (24)
in shaft keyway. Install a lathe dog on the drive end
of the shaft with the V" notch positioned over the
shaft key.
Use a long piece of heavy bar stock and the lathe
dog as shown in Figure E−2 to block shaft rotation.
Use caution not to damage the shaft or keyway.
Lathe Dog Arm
V" Notch
Shaft Key
Impeller
Shaft
Lathe Dog
Setscrew
Heavy
Bar Stock
Work Surface
Figure E−2. Blocking Shaft Rotation
Loosen the two setscrews (63) and remove the im-
peller nut (65).
NOTE
If necessary, heat the impeller with a torch to aid re-
moval.
The impeller is very heavy and could be
damaged and/or could injure personnel if
it is dropped. Use extreme caution when
performing the following procedure to pre-
vent dropping the impeller when it breaks
loose from the shaft.
The impeller is secured to the shaft by the woodruff
key (81) and a taper fit.To remove the impeller, in-
stall two 3/8-16 UNC capscrews (not supplied) in
the tapped holes in the impeller. Use a gear puller
to preload the impeller. Strike the gear puller shaft
with a hammer to break the impeller loose. Re-
move the impeller and woodruff key.
NOTE
An alternate method of removing the impeller is to
install two wedges 180
_ apart between the impeller
and the seal plate. Tap the wedges alternately until
the impeller breaks loose. If necessary, position a
piece of round bar stock against the end of the im-
peller shaft and strike the bar stock with a hammer