[Type text]
2850-254-00
2
8/2015
Specifications Information and Repair Parts Manual
2850-99
x
Self-Priming Centrifugal Pedestal Pumps
MAINTENANCE
Make certain that unit is disconnected from power source before
attempting to service or remove any components!
MECHANICAL SEAL REPLACEMENT
Refer to Figure 1.
IMPORTANT:
Always replace both the seal seat and the seal head to
ensure proper mating of components! Handle the mechanical seal
replacement carefully as the precision lapped faces can be damaged
easily.
1.
Disassemble the bearing housing (Ref. No. 5) and gasket
(Ref. No. 6) from the pump casing (Ref. No. 11) by removing
the 4 hex head cap screws (Ref. No. 13).
2.
Unscrew the impeller, (right hand thread, Ref. No. 10).
3.
Carefully pry up on the seal cartridge (Ref. No. 8) using two
large screwdrivers. Often, this portion of the seal can be
removed by pulling off with your fingers.
4.
Remove the shaft bearing assembly (Ref. No. 3) by first
removing the snap ring (Ref. No. 1) and shims. Push the
shaft bearing assembly out of the bearing housing by
tapping on the threaded end of the shaft with a rawhide
mallet or block of wood and hammer. As shaft is being pulled
from the housing, the shaft slinger (Ref. No. 4) between the
seal
and the bearing will fall free.
5.
Pry the seal seat (Ref. No. 7) from the cavity in the bearing
housing.
6.
Replace shaft bearing assembly by sliding the assembly into
the housing, threaded shaft first. As shaft end emerges from
bearing cavity before it enters into seal cavity, slip the rubber
slinger washer (Ref. No. 4) up from the underside, over the
end of the shaft. Some manipulation through the seal cavity
opening may be required. Push shaft bearing assembly
home by gently tapping on keyway end of shaft with a
rawhide mallet. Replace snap ring and shims.
7.
Carefully wipe the surface of the ceramic seat with a clean
cloth.
8.
Wet the rubber portion of the ceramic seat with a light
coating of soapy water.
9.
Press the seal seat squarely into the cavity in the bearing
housing. If the seal seat does not press squarely into the
cavity, it can be adjusted in place by pushing on it with a
piece of pipe.
NOTE:
Always use a piece of cardboard between the pipe and the
seal seat to avoid scratching the seal seat. This is a lapped surface
and must be handled very carefully.
10.
After the seal is in place, be sure that the face is clean and
has not been scratched or cracked.
11.
Using a clean cloth, wipe the shaft and make sure that it is
perfectly clean.
12.
Apply a light coating of soapy water on the inside of the
rubber drive ring inside the seal cartridge assembly. Slide
the seal assembly onto the shaft (with the sealing face first),
sliding the rubber drive ring just up over the shaft shoulder.
Do not touch or wipe the seal head.
13.
Replace any shim washers (Ref. No. 9) you may have
removed in disassembly.
14.
Screw the impeller back in place, tightening until it is against
the shoulder provided on the shaft.
15.
Replace pump casing on the bearing housing, using a new
gasket to prevent leakage. Turn shaft by hand to ensure free
rotation. If striking of the impeller on the pump casing is
noted, disassemble and remove shim washers as required.
BEARING HOUSING SERVICE
1.
Remove front pump assembly as described under
“Mechanical Seal Replacement”
2.
Remove shaft/bearing assembly (Ref. No. 3) by first
removing retaining ring (Ref. No. 1). Push shaft/bearing
assembly out of pedestal (Ref. No. 5) by rapping on
threaded end of shaft with a rawhide mallet, or block of
wood and a hammer.
3.
Replace shaft/bearing assembly by sliding assembly into
housing threaded end first. Push shaft bearing assembly
completely in by gently tapping on keyway end of shaft with
a rawhide mallet. Replace retaining ring.
4.
Reassemble pump as described in “Mechanical Seal
Replacement”.
SHIM ADJUSTMENT
1.
When installing a replacement, impeller (Ref. No. 5) or
casing (Ref. No. 11) it may be necessary to vary the number
of impeller shims (Ref. No. 9) that will be required. This is
easily done by adding one shim more than was removed
and reassembling pump as described in MECHANICAL
SEAL REPLACEMENT section.
NOTE:
When adding or removing shims, it is best to proceed with a
0.010" increment each time. While tightening unit together, turn shaft
and feel for shaft seizing. If shaft begins to seize before fasteners are
completely tight, disassemble pump and remove one shim and repeat
assembly.
2.
Once having added one shim more than original, ensure that
casing and pedestal are firmly fitted (check fasteners Ref.
No. 13). When pump shaft turns freely add shims until it
does strike, then remove a 0.010" shim. This should allow
proper clearance.
3.
Proper running clearance for impeller should be as close as
possible to volute without striking; maximum clearance is
1/32" (0.032").
4.
Follow above procedure until proper clearance is obtained.
This will ensure maximum performance.
Summary of Contents for 2850-99
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