LCC
19
7.5.4
Installing End Covers and Seals
The standard bearing housing shaft seal is the Inpro VBX
type labyrinth seal. Other seal types may be available
including the Caterpillar Duo-Cone seal for underwater
bearing assemblies. See your arrangement drawing for
specific information regarding these alternate seal types.
Prior to installation, press the Inpro shaft seals into each
end cover, ensuring that the contaminant expulsion port
and lubrication return trough are located at the 6 o’clock
(bottom) position. If possible, use a hand operated arbor
press instead of a hydraulic press to improve control of the
pressing operation. You will be overcoming a light
interference fit and may shear off a portion of the outer
diameter o-ring, however, this is normal and indicates a
secure fit.
Slide end covers with gaskets and Inpro seals over the
shaft at each end, again making certain that the
contaminant expulsion port and lubrication return trough
are located at the bottom. Use O-Ring lubricant, Parker
O-Lube or Parker Super-O-Lube to lubricate the inner
diameter o-rings against the shaft. Take special care
when running the seal over the shaft keyway to avoid
cutting the o-ring. If necessary, lightly file the keyway
edges to avoid this problem.
After bolting the end covers in place, rotate the shaft by
hand. There should be no frictional contact between the
rotating and stationary parts of the Inpro seal. Any
rubbing or axial movement in the seal may indicate
misalignment. If this is the case, tap lightly into alignment.
Note that the drive side end cover clamps against the
outer race of the taper roller bearing and may not fit flush
against the housing. No shimming is necessary. A gap
of up to 1mm (0.04 in.) is acceptable and within the
tolerance of the parts. Any larger gap may indicate that
the taper roller bearing is not fully seated into the housing.
For oil lubrication see Section 7.2.2
Figure 7.5-2 VBX Inpro Seal for LCC
7.5.5
Mounting Shaft Sleeve
In mounting the shaft sleeve, do not allow anti-seize
compound to come in contact with any of the
axial faces
of the shaft sleeve, including the impeller contacting face
or the face in contact with the shaft shoulder. For ease of
removal, a light coating of anti-seize compound should be
applied to the inner diameter of the shaft sleeve.
Lubrication at any of shaft sleeve or shaft shoulder
faces may result in overloading and breakage of
the shaft.
In many cases, there will be an o-ring which must be
placed on the shaft first. As the shaft sleeve is pushed into
position, this o-ring should be completely forced into the
shaft sleeve recess.
If a non-split lantern ring or throat bushing is being used, it
should be placed onto the shaft sleeve at this time.
Figure 7.5-3 Standard LCC Shaft Sleeve Arrangement
7.5.6
Mounting Stuffing Box
7.5.6.1 Stuffing
Box
The stuffing box should be mounted so that the sealing
water tap is on or near the vertical centerline. This will
position the gland studs at 9 o’clock and 3 o’clock for easy
access. Note that the small stuffing boxes have a single
inlet while the larger sizes have a second port that can be
used for additional flow or have a pipe plug installed.
Location of the stuffing box is provided by a close
clearance fit with the pedestal. No additional centering
operation is required.
In some cases, a separate stuffing box wear plate may be
provided. Apply RTV to the back of the wear plate before
bolting it to the stuffing box.
See Figure 4.3-4 for typical stuffing box arrangement.
7.5.6.2 Packing (non-expeller)
The packing arrangement consists of a lead ring, followed
by a standard lantern ring, and then three more rings of
packing (two rings for 70mm shaft).The packing should be
well coated with water resistant grease during assembly.
See figure 4.3-4.
7.5.6.3 Packing
(expeller)
As of 2004, the static seal for the expeller has been
modified. The forward ring of packing and the standard
lantern ring have been replaced with a low flow throat
bushing. The throat bushing is followed by a ring of
packing, a special lantern ring, and then a second ring of
packing.. All rings of packing should be well coated with
water resistant grease during assembly. See figure 4.3-5
There is an additional rear tap on the stuffing box for
grease lubrication of the packing, allowing the primary
(forward) taps to be reserved for intermittent flush water,
when needed. When the water purge port is not utilized, a
pipe plug should be used to seal the port opening.
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