Gorman-Rupp Pumps 12C20-B 1341727 and up - Manual (Page 28)

OM-00608 10 SERIES
MAINTENANCE & REPAIR PAGE E - 5
Pump Casing Removal
Death or serious personal injury and
damage to the pump or components
can occur if proper lifting procedures
are not observed. Make certain that
hoists, chains, slings or cables are in
good working condition and of suffi­
cient capacity and that they are posi­
tioned so that loads will be balanced
and the pump or components will not be
damaged when lifting. Suction and dis­
charge hoses and piping must be re­
moved from the pump before lifting. Lift
the pump or component only as high as
necessary and keep personnel away
from suspended objects.
To service the impeller (2), wear plate assembly
(42) and seal assembly (3), disconnect the dis­
charge piping. Remove the hardware securing the
pump casing (1) to the base.
Remove the nuts (39) securing the pump casing
and gasket set (41) to the pedestal (31) and seal
plate (40). Separate the casing from the seal plate
and pedestal. Tie and tag any leveling shims used
under the pump mounting feet to ease reassembly.
Remove the gasket set (41) from the pedestal and
seal plate. Tie and tag the gaskets, or measure
and record their thickness for ease of reassembly.
Tie and tag any leveling shims used under the cas­
ing mounting feet to ease reassembly. Clean the
mating surfaces of the seal plate and pump casing.
Impeller Removal
Before removing the impeller, remove the bottle oil­
er and piping (63, 64 and 65). Remove the seal
drain plug (37) and drain the oil from the seal cavity
to prevent the oil from escaping when the impeller
is removed. Clean and reinstall the drain plug.
Disconnect the power source.
Immobilize the impeller by wedging a block wood
between the vanes. If removed, install the shaft key
(26). Install a lathe dog on the drive end of the shaft
(28) with the “V” notch positioned over the shaft
keyway.
With the impeller rotation still blocked, strike the
lathe dog sharply in a counterclockwise direction
(when facing the drive end of the shaft). The impel­
ler may also be loosened by using a long piece of
heavy bar stock to pry against the arm of the lathe
dog in a counterclockwise direction (when facing
the drive end of the shaft) as shown in Figure 2.
Use caution not to damage the shaft or keyway.
When the impeller breaks loose, remove the lathe
dog and wood block and unscrew the impeller
from the shaft.
Turn
Counterclockwise
Lathe Dog Arm
“V” Notch
Shaft Key
Impeller Shaft
Lathe Dog
Setscrew
Heavy
Bar Stock
Figure E-2. Loosening Impeller
Unscrew the impeller from the shaft. Use caution
when removing the impeller; tension on the seal
spring will be released as the impeller is un­
screwed.
Inspect the impeller and replace it if cracked or
badly worn. Slide the impeller adjusting shims (62)
off the impeller shaft. Tie and tag the shims or mea­
sure and record their thickness for ease of reas­
sembly.
Seal Removal and Disassembly
Remove the spring centering washer (60) and seal
spring. Slide the shaft sleeve (61) and rotating por­
tion of the seal off the shaft as a single unit. Apply oil
to the sleeve and work it up under the bellows.
Slide the rotating portion of the seal off the sleeve.
Remove the air vent and piping (15, 16 and 17)
from the seal plate (40). Slide the seal plate and
stationary portion of the seal assembly off the shaft