Gorman-Rupp Pumps 16C2-F4L 1237525 thru 1319250 - Manual (Page 38)

10 SERIES OM−00725
MAINTENANCE & REPAIR PAGE E − 14
Impeller Installation And Adjustment
(Figure 2)
Inspect the impeller, and replace it if cracked or
badly worn.
The shaft and impeller threads must be
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 as previously removed, and screw the im-
peller 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 .025 to .040 inch (0,64 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.
Remove the two capscrews temporarily holding
the seal plate, and install the same thickness of
casing gaskets (49) as previously removed. Se-
cure the seal plate and pump casing to the inter-
mediate with the nuts (16). 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 (49) until the impeller scrapes
against the wear plate when the shaft is turned. Af-
ter the impeller scrapes, 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 (73), 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 check valve seat
(65). Align the adaptor with the seat hole, and se-
cure the assembly with the check valve pin (74).
NOTE
If the suction flange or check valve seat was re-
moved, replace the respective gaskets, and apply
‘Permatex Aviation No. 3 Form-A-Gasket’ or equiva-
lent compound to the mating surfaces.
Back Cover Installation
(Figure 2)
If the wear plate (51) was removed for replace-
ment, carefully center it on the back cover and se-