rotating impeller and the stationary casing wearing rings. For proper hydraulic performance these clear-
ances should be maintained as indicated below. Ring should be replaced when clearances have worn to
those listed under replacement clearance.
Table shows original clearances and suggested replacement clearances as follows:
Table 3: Recommended clearances
Ring Bore Dia. (inches)
Diametrical Clearance (inches)
Original
Replacement
under 2" Dia.
0.010-0.014
0.020-0.024
2" to 2-1/2" Dia.
0.011-0.015
0.021-0.025
2-1/2" to 3-1/2" Dia.
0.014-0.018
0.024-0.028
3-1/2" to 4 -1/2" Dia.
0.016-0.020
0.026-0.030
over 4-1/2" Dia.
0.018-0.022
0.028-0.032
To check ring clearances or for replacement proceed as follows:
1.
Shut off all piping and disconnect suction piping.
2.
Drain liquid from pump.
3.
Unscrew nuts from studs (356) and remove cover (182) from casing.
If pump has only a suction wearing ring, as indicated in
7.4 Sectional views, parts list and inter-
changeability tables on page 29
, then check outside diameter of impeller hub and inside diameter
of casing wearing ring in casing cover.
If pump is designed with two wearing rings:
4.
Remove impeller nut (304) and washer (199).
5.
By use of a suitable puller similar to that shown in
Figure 10: Impeller puller on page 28
peller from shaft. (Puller must push against shaft as shown. Do not use a type that pulls from
casing). All impellers are provided with two tapped holes to facilitate use of puller.
6.
Check diameters of both hubs and rings. If clearances are excessive, the rings should be re-
placed. See recommended clearances table above.
7.
Remove rings from cover and casing.
8.
Clean bore in which rings seat and press new rings evenly into place.
9.
Replace impeller, washer, nut and casing cover as directed in
Figure 10: Impeller puller on page
7.6 Replacing impeller
1.
Shut off all piping and disconnect suction piping.
2.
Drain liquid from pump.
3.
Unscrew nuts on studs (356) and remove suction cover (182) from casing.
4.
Remove impeller nut (304) and impeller washer (199) from shaft.
5.
By use of a suitable puller similar to that shown in
Figure 10: Impeller puller on page 28
peller from shaft. (Puller must push against shaft as shown. Do not use a type that pulls from
casing). All impellers are provided with two tapped holes to facilitate use of puller.
6.
Check diameters of impeller hubs and wearing rings to determine if new rings are needed. Re-
place rings in suction cover or casing if necessary. Refer to
Table 3: Recommended clearances
.
7.
Slide new impeller on shaft as far as possible.
8.
Using a soft metal hammer, tap evenly on center of impeller until shaft threads protrude beyond
impeller.
7.6 Replacing impeller
32
Model 3755 Installation, Operation, and Maintenance Manual
Содержание Goulds Pumps 3755
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