Gorman-Rupp Pumps U6B60S-B 1289612 and up - Manual (Page 38)

OM-05669 SUPER U SERIES
MAINTENANCE & REPAIR PAGE E - 15
Suction Check Valve Installation
(Figure 1)
Inspect the check valve assembly (53), and re­
place it if badly worn.
NOTE
The check valve assembly must be replaced as a
complete unit. Individual parts are not sold sepa­
rately.
Reach through the back cover opening with the
check valve and position the check valve adaptor
in the mounting slot in the suction flange (49). Align
the adaptor with the flange hole, and secure the as­
sembly with the check valve pin (54).
NOTE
If the suction or discharge flanges were removed,
replace the respective gaskets, apply `Permatex
Aviation No. 3 Form‐A‐Gasket' or equivalent com­
pound to the mating surfaces, and secure them to
the pump casing with the attaching hardware.
Back Cover Installation And Adjustment
(Figure 1 and 9)
If the wear plate (28) was removed for replace­
ment, carefully center it on the back cover assy (33)
and secure it with the hardware (30 and 31). The
wear plate must be concentric to prevent binding
when the back cover is installed.
Clearance between the impeller and wear plate is
adjusted using four adjusting screws and locking
collars. There are 18 detents on the I.D. of each
locking collar. Indexing the collars one detent on
the adjusting screws represents approximately
.005 inch (0,13 mm) of wear plate clearance. The
recommended clearance between the wear plate
and the impeller is .003 to .005 inch (0,07 to 0,125
mm).
USE TWO
OPPOSING
BACK COVER NUTS
TO PRESS
BACK COVER
INTO PUMP
CASING USE TWO REMAINING
ADJUSTING SCREWS AND
LOCKING COLLARS TO
SET FACE CLEARANCE
INDEX COLLARS 3
DETENTS COUNTER‐
CLOCKWISE, THEN
TURN CLOCKWISE
UNTIL SCREW
HOLES ALIGN
Figure 9. Installing and Adjusting Back Cover
Replace the wear plate and back cover O‐rings (29
and 32) 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.
Screw the four adjusting screws (46) 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 (44) and
slide it into the pump casing. Use two back cover
nuts (45) 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 back cover 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 back cover 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