Gorman-Rupp Pumps T8A61S-B /F,/FM - Manual (Page 35)

OM-05476 SUPER T SERIES
MAINTENANCE & REPAIR PAGE E - 13
the threads can cause the impeller to seize
to the shaft, making future removal difficult
or impossible without damage to the im­
peller or shaft.
Install the same thickness of impeller adjusting
shims (31) as previously removed. Apply `Never‐
Seez' or equivalent to the shaft threads and screw
the impeller onto the shaft until tight. Be sure the
seal spring seats squarely on the back side of the
impeller.
NOTE
At the slightest sign of binding, immediately back
the impeller off, and check the threads for dirt. Do
not try to force the impeller onto the shaft.
A clearance of .025 to .040 inch (0,64 to 1,02 mm)
between the impeller and the seal plate is recom­
mended for maximum pump efficiency. Measure
this clearance, and add or remove impeller adjust­
ing shims as required.
NOTE
If the rotating assembly has been installed in the
pump casing, this clearance may be measured by
reaching through the priming port with a feeler
gauge.
Proceed with Rotating Assembly Installation be­
fore installing the impeller capscrew and washer
(24 and 25). The rotating assembly must be in­
stalled in the pump casing in order to torque the im­
peller capscrew.
After the rotating assembly is installed in the pump
casing, coat the threads of the impeller capscrew
(25) with `Never‐Seez' or equivalent compound,
and install the impeller washer (24) and capscrew;
torque the capscrew to 90 ft. lbs. (1080 in. lbs. or
12,4 m. kg.).
Rotating Assembly Installation
(Figure 1)
Install the bearing housing and seal plate O‐rings
(20 and 21) and lubricate them with light grease.
Ease the rotating assembly into the pump casing
using the installation tool. Be careful not to dam­
age the O‐rings.
Install the pump casing ring (14), and secure it to
the rotating assembly with the inner hardware (17
and 18).
NOTE
The inner capscrews are 1/4 inch (3,2 mm) shorter
than the outer capscrews.
Install an equal thickness of rotating assembly
shims (13) under the pump casing ring, and secure
the ring to the pump casing with the outer hard­
ware (15 and 16).
To set the impeller and wear plate clearance, refer
to the Back Cover Installation And Adjustment.
Suction Check Valve Installation
(Figure 1)
Inspect the check valve assembly (46), 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 (45). Align
the adaptor with the flange hole, and secure the as­
sembly with the check valve pin (3).
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 7)
If the wear plate (22) was removed for replace­
ment, carefully center it on the back cover and se­
cure it with the hardware (35 and 36). 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