Crown CT4QP Series, Installation And Operation Manual

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(item 40) The volute is normally held in the case by three
stainless steel studs and cap screws (some larger sizes use 5
studs). The volute can be removed only after the hatch or case
cover (item 24) has been removed.
(item 41) Horse shoe shims are used between the case and the
pedestal permitting external adjustment of clearance between
impeller and volute wear surface (item 26) without dismantling
the pump. Loosen 6 nuts, remove or add shims in equal
amounts at each location, and retighten the 6 nuts until the
proper clearance is obtained. The thinnest shims are
approximately .015 inches thick. O-ring (item 32) provides the
necessary sealing at all times.
SECTION G: SHAFT SEAL REPLACEMENT
G-1) Replacement Through Hatch Cover:
G-1.1) Disassembly:
All parts of the pump are easily dismantled by simply removing
nuts and screws. Rotating parts of the shaft seal grip the shaft
by friction and may be frozen to the shaft through long usage.
If the mechanical shaft seal is not leaking and it is necessary to
dismantle part of the pump for inspection or cleaning,
DO NOT
disturb the shaft seal other than its spring if the impeller is
removed. Once a shaft seal has been in operation it cannot be
reused without leaking.
Remove hatch cover (24), by removing wing nuts and prying
the cover off. Now remove capnuts (40) and pull the volute (29)
and seal Plate (31) out of the pump case, (See Figure 3).
Remove the impeller nut, it is a standard right hand thread,
remove impeller washer, and then remove the impeller (28). The
impeller has been provided with two drilled and tapped holes for
a wheel puller, if necessary use a wheel puller to remove the
impeller.
FIGURE 3
Typical Pump Cut-away
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