Gorman-Rupp Pumps 16C20-F5L 1338868 and up - Manual (Page 35)

10 SERIES OM−02616
MAINTENANCE & REPAIR PAGE E − 14
seal plate to the intermediate with two capscrews
and nuts (1/2 UNC by 1−1/2 inch long, not
supplied).
Assemble the O-rings into the stationary seat.
Press the stationary element into the stationary
seat with the chamfered side facing away from the
seat. Press this subassembly into the seal plate
bore until fully seated. A push tube cut from a
length of plastic pipe would aid this installation.
The I.D. of the tube should be approximately the
same as the I.D. of the seal spring.
Subassemble the rotating element into the rotating
portion of the seal assembly with the chamfered
side facing out. Slide the rotating portion of the seal
assembly onto the shaft sleeve (33) with the rotat-
ing element facing the chamfered end of the
sleeve. Slide the sleeve onto the shaft until the seal
elements contact and the sleeve bottoms against
the shaft shoulder. Be careful not to roll or damage
the lip of the seal plate oil seal (22).
Install the seal spring and spring holder.
Reinstall the bottle oiler and piping (34, 35 and 36)
and the air vent and piping (17, 18 and 19).
Lubricate the seal as indicated in LUBRICATION,
after the impeller has been installed.
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 (32) 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 .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 (55) 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.
NOTE
If the pump has been completely disassembled, it
is recommended that the wear plate (57) and back
cover assembly (62) be reinstalled at this point. The
back cover and wear plate must be in place to ad-
just the impeller face clearance.
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 (55) 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