Gorman-Rupp Pumps T2A3-B /F,/FM,/WW - Manual (Page 36)

OM-05136 T SERIES
MAINTENANCE & REPAIR PAGE E - 13
and install the impeller washer (31) and capscrew;
torque the capscrew to 90 ft. lbs. (1080 in. lbs. or
12,4 m. kg.).
Rotating Assembly Installation
(Figure 1)
NOTE
If the pump has been completely disassembled, it
is recommended that the back cover assembly be
reinstalled at this point. The back cover assembly
must be in place to adjust the impeller face clear­
ance.
Install the bearing housing and seal plate O‐rings
(12 and 17) and lubricate them with light grease.
Ease the rotating assembly into the pump casing.
Be careful not to damage the O‐rings.
Install the four sets of rotating assembly adjusting
shims (16) using the same thickness as previously
removed. Secure the rotating assembly to the
pump casing with the hardware (14 and 15). Do
not fully tighten the capscrews until the back cover
has been installed and the impeller face clearance
has been set.
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 can be obtained by removing an equal
amount of shims from each rotating assembly
shim set until the impeller scrapes against the wear
plate when the shaft is turned by hand. After the im­
peller scrapes, add approximately .015 inch (0,4
mm) of shims to each shim set.
Suction Check Valve Installation
(Figure 1)
Inspect the check valve assembly (36) and replace
it if badly worn.
NOTE
The check valve assembly must be replaced as a
complete unit. Individual parts are not sold sepa­
rately.
Position the check valve in the mounting slot in the
pump casing (1) with the grooves in the rubber to­
ward the inside of the pump. Secure the assembly
with the check valve cover (2) and the hardware (3
and 4)
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
(Figure 1)
If the wear plate (18) was removed for replace­
ment, carefully center it on the back cover (26) and
secure it with the hardware (19 and 20). The wear
plate must be concentric to prevent binding when
the back cover is installed.
Replace the back cover O‐ring (22), and lubricate it
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. Slide the back cover as­
sembly into the pump casing. Be sure the wear
plate does not bind against the impeller.
NOTE
To ease future disassembly, apply a film of grease
or `Never‐Seez' on the back cover shoulder, or any
surface which contacts the pump casing. This ac­
tion will reduce rust and scale build‐up.
Secure the back cover assembly by tightening the
back cover nuts (23) evenly. Do not over‐tighten
the nuts; they should be just tight enough to en­
sure a good seal at the back cover shoulder. Be
sure the wear plate does not bind against the cas­
ing.
PRESSURE RELIEF VALVE
MAINTENANCE
(Figure 1)
The back cover is equipped with a pressure relief
valve (30) to provide additional safety for the pump
and operator (refer to Liquid Temperature And
Overheating in OPERATION).