Xylem P81875F Series HSC and HSC-S Centrifugal Pump - Manual (Page 17)

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5. Packing Seal
When a pump with packing is first started it is advisable to
have the packing slightly loose without causing an air leak. As
the pump runs in, gradually tighten the gland bolts evenly. The
gland should never be drawn to the point where packing is
compressed too tightly and no leakage occurs. This will cause
the packing to burn, score the shaft sleeve and prevent liquid
from circulating through the stuffing box cooling the package.
NOTE: Eccentric run-out of the shaft or sleeve through the
packing could result in excessive leakage that cannot be com-
pensated for. Correction of this defect requires shaft and/or
sleeve replacement. Packing should be checked frequently
and replaced as service indicates. Six months might be a rea-
sonable expected life, depending on the operating conditions.
6. Cleaning Without Dismantling Pump
A short section of pipe so designed that it can be readily
dropped out of the line can be installed adjacent to the suction
flange. With this arrangement, any matter clogging the
impeller is accessible by removing the pipe section.
If the pump cannot be freed of clogging after the above
methods have been tried, dismantle the unit as previously
described to locate the trouble.
III. Series HSC & HSC-S Pump
A. DISASSEMBLY AND ASSEMBLY PROCEDURE
The procedures outlined in this section cover the dismantling
and reassembly of the Series HSC pump construction.
A. Series HSC pump with mechanical seals on the shaft.
B. Series HSC pump with mechanical seals on shaft
sleeves.
C. Series HSC pump with packing.
Each procedure provides the step-by-step requirements for
dismantling and then reassembling the pump, depending
upon the type of seal used. Each procedure is complete within
itself, so that reference to other sections is not required.
When working on the pump, use accepted mechanical prac-
tices to avoid unnecessary damage to parts. Check clear-
ances and conditions of parts when pump is dismantled and
replace if necessary. Steps should usually be taken to restore
impeller and casing ring clearance when it exceeds three
times the original clearance.