Gorman-Rupp Pumps 14C20-F3L 1319349 and up - Manual (Page 35)

10 SERIES OM−03413
MAINTENANCE & REPAIR PAGE E − 14
completely clean before reinstalling the im-
peller. Even the slightest amount of dirt on
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 (76) as previously removed, and screw the
impeller (2) onto the shaft until tight.
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 .020 to .040 inch (0,51 to 1,02 mm)
between the impeller and the seal plate is neces-
sary for maximum pump efficiency. Measure this
clearance, and add or remove impeller adjusting
shims as required.
NOTE
If the pump has been completely disassembled, it
is recommended that the wear plate (42) and back
cover assembly (50) be reinstalled at this point. The
back cover and wear plate must be in place to ad-
just the impeller face clearance.
Install the same thickness of pump casing gaskets
(40 and 41) as previously removed. Secure the
pump casing to the intermediate with the nuts (39).
Do not fully tighten the nuts until 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 must be set after installing the back
cover, by adding or removing gaskets in the pump
casing gasket set (40 and 41) until the impeller
binds against the wear plate when the shaft is
turned. After the impeller binds, add approximately
.010 inch (0,25 mm) of gaskets.
NOTE
An alternate method of adjusting this clearance is to
reach through the discharge port with a feeler
gauge and measure the gap. Add or subtract pump
casing gaskets accordingly.
If a lifting eye was used to move the pump casing,
be sure to remove the lifting eye from the pump
casing.
Do not attempt to lift the complete pump
unit using the lifting eye. It is designed
to facilitate removal or installation of in-
dividual components only. Additional
weight may result in damage to the
pump or failure of the eye bolt.
Suction Check Valve Installation
(Figure 2)
Inspect the check valve assembly (58), 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 as-
sembled check valve, and position the check valve
adaptor in the mounting slot in the suction flange
(61). Align the adaptor with the flange hole and se-
cure the assembly with the check valve pin (64).
If the suction flange was removed, replace the gas-
ket (65), and apply ‘Permatex Aviation No. 3 Form-
A-Gasket’ or equivalent compound to the mating
surfaces.
Secure the suction flange (60) to the pump casing
with the nuts (57 and 63).
Back Cover Installation
(Figure 2)
If the wear plate (42) was removed for replace-
ment, carefully center it on the back cover (52) and
secure it with the hardware (44 and 45). The wear
plate must be concentric to prevent binding when
the back cover is installed.
Clean any scale or debris from the contacting sur-
faces on the pump casing that might interfere or
prevent a good seal with the back cover. Replace