Crown CT4QP Series, Installation And Operation Manual

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Remove the seal spring and spring holder. At this time the
rotating portion and the seat can be removed without further
dissassembling of the pump. However, it is generally easier to
remove the four (4) nuts that hold the pump side in place and
by using two pry bars, force the pump side with the old seal off
the shaft. The grease cup (38) must first be removed.
By using this method the lip seal (34) can be be replaced and
the seal seat can be easily removed and cleaned. Use care in
cleaning the shaft because nicks can allow the new seal to leak.
At this time the shaft slinger used on single seal applications,
should be examined and replaced if necessary.
Inspect o-ring (32) carefully for cuts or nicks. Clean the groove
in the pump side and the mating bore in the pump case carefully
and grease at reassembly.
G-1.2) Reassembly:
After the seals have been replaced and the impeller secured
on the shaft (see Table 2), Place the seal plate (31) over the
studs of the volute (29) and insert this assembly over the
impeller with the volute studs projecting through the case.
Replace the cap or self locking nuts and tighten them (
only
finger tight at this time ). NOTE: On the CT6QP model it is
necessary to insert the seal plate over the impeller , then insert
the volute.
Replace o-ring (30) on the volute, and o-rings (23) and (25) on
the hatch cover, grease these o-rings and the areas they
contact thoroughly. Now insert the hatch cover (24) and
securely tighten the wing nuts. Normally these wing nuts can
be tightened sufficiently by hand. This method of securing the
hatch cover first, centers the volute properly over the impeller.
Tighten the cap nuts (40) that hold the volute in place.
The clearance between an open faced impeller and its wear
surface in the volute is set at the factory to approximately .015
inches. This clearance is readjustable on all pumps by adding
or removing of horseshoe shims (33) located at the bearing
adapter flange, or on small units by relocating the shaft at the
clamping arrangement. Add or remove shims until the impeller
rubs slightly, then add one thin shim (.015 thick) at each
location and tighten the nuts securely.
G-2) Replacement By Removing Pedestal:
The belt tension must be relieved and the guard and the belts
removed. Then remove the pedestal bolts attaching the
pedestal to the base.
Remove the six capscrews, from the studs that contain the
horseshoe shims. Now, the pedestal assembly (35) can be
pulled or pryed from the case.
After removing the pedestal assembly, the impeller, the old
seal, and pump side parts are removed. First remove the
impeller nut, it is a standard right hand thread, 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. Remove the the four (4) nuts that
hold the pump side in place and by using two pry bars, force
the pump side with the old seal off the shaft. The grease cup
(38) must first be removed.
The lip seal (34) can be be replaced and the seal seat can be
easily removed and cleaned. Use care in cleaning the shaft
because nicks can allow the new seal to leak. At this time the
shaft slinger used on single seal applications, should be
examined and replaced if necessary.
Inspect o-ring (32) carefully for cuts or nicks. Clean the groove
in the pump side and the mating bore in the pump case
carefully and grease at reassembly.
Reassemble pedestal assembly into pump and set the
clearance by adding or removing shims (33) until the impeller
rubs slightly, then add one thin shim (.015 thick) at each
location and tighten the nuts securely.
G-3) Single Seal Installation:
Carefully identify all the parts in Figures 6 and 7, and familiarize
yourself with their part names.
The mating ring (7) and seat (1) have been precision lapped
and must not be scratched or cracked during assembly. Also,
cleanliness is of utmost importance.
STEP 1:
Make sure that the shaft and seat areas in the pump side are
as clean as possible. Shoulder "A" on the shaft must not be
sharp, but neatly rounded and polished to a 1/32" radius. This
radius and the shaft, on which the rubber bellows grips, must
be polished with 180 to 240 grit emery cloth. The seal will install
relatively easy if the shaft is properly polished.
STEP 2:
Install the seat assembly (1 and 2 or 1A and 2A, see Figure 7),
in the bottom of the pump side using SAE#90 oil on the rubber
parts. They may install easier by first inserting the rubber part
and then sliding the seat part into the rubber. All of this must
be done with the
fingers only .
FIGURE 4
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