Gorman-Rupp Pumps T8A60S-F6L 1278434 thru 1318430 - Manual (Page 49)

OM−05517 SUPER T SERIES
MAINTENANCE & REPAIR PAGE E − 20
cure it with the hardware (24 and 25). The wear
plate must be concentric to prevent binding when
the back cover is installed.
The clearance between the impeller and wear plate
is adjusted using four adjusting screws (42) and
locking collars (34). There are 18 detents on the
I.D. of each locking collar. Indexing the collars one
detent on the adjusting screws represents approxi-
mately .005 inch (0,13 mm) of wear plate clear-
ance. The recommended clearance between the
wear plate and the impeller is .010 to .020 inch
(0,25 to 0,50 mm).
Replace the back cover and wear plate O-rings (22
and 27) and lubricate them with a generous
amount of No. 2 grease. Clean any scale or debris
from the contacting surfaces in the pump casing
that might interfere or prevent a good seal with the
back cover.
USE TWO
OPPOSING
HAND NUTS
TO PRESS
BACK COVER
INTO PUMP
CASING
USE TWO REMAINING
ADJUSTING SCREWS
AND LOCKING COL-
LARS TO SET FACE
CLEARANCE
INDEX COLLARS 3
DETENTS COUNTER-
CLOCKWISE, THEN
TURN CLOCKWISE
UNTIL SCREW
HOLES ALIGN
Figure 12. Installing and Adjusting Back Cover
Screw the four adjusting screws (42) into the
tapped holes in the back cover plate until they are
just flush with the machined surface on the back
side of the cover plate.
Align the back cover plate over the studs (40) and
slide it into the pump casing. Use two hand nuts
(41) on diagonally opposing studs to press the
back cover into the pump casing until the wear
plate just touches the impeller when the shaft is
turned by hand. Tighten the hand nuts evenly to
avoid binding.
With the wear plate just touching the impeller, turn
the two free adjusting screws until they engage the
pump casing. Position the locking collars over the
adjusting screws so the holes in the collars for the
locking screws align approximately with the holes
in the cover plate.
Loosen the hand nuts used to press the back cover
into the pump casing one full turn.
Pull the collars off the adjusting screws, index them
three detents counterclockwise, and reinstall the
collars on the adjusting screws. Use the collars to
turn the adjusting screws clockwise until the holes
in the locking collars realign with the tapped screw
holes in the back cover plate. Secure the locking
collars to the back cover plate with the hardware
(35 and 36). Install the two remaining hand nuts
snugly against the adjusting screws.
Remove the first two hand nuts from their studs.
Turn the adjusting screws clockwise until they en-
gage the pump casing. Install the locking collars
and hardware (35 and 36). Reinstall the hand nuts.
Be sure the wear plate does not scrape against the
impeller.
Over time it may be necessary to repeat the adjust-
ment process to compensate for normal wear be-
tween the impeller and wear plate. When all of the
adjustment has been used on the back cover side
of the pump, an additional 0.125 inch (3,2 mm) of
adjustment may be obtained by removing the ro-
tating assembly adjusting shims (13).
Allow an installed pump to completely cool before
draining liquid from the pump casing. Remove the
back cover. Remove the rotating assembly adjust-
ing shims, then reinstall the hardware securing the
casing ring (14) and rotating assembly to the pump
casing. Perform the back cover adjustment proce-
dure described above to obtain the proper face
clearance.
Securing Pump End To Engine
(Figure 5)
Install the shaft key (16, Figure 4) in the shaft key-
way. Position the flexible portion of the coupling as-
sembly (3) on the shaft as shown in Figure 5.
Align the keyway in the bushing (2) with the shaft
key, and slide it onto the shaft until it is just flush