Flowserve CPXV fitted with Mark 3 ASME hydraulics - Manual (Page 28)

CPXV with Mark 3 ASME hydraulics ENGLISH 71569291 12-14
Page 28 of 44
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j) Check that the shaft can turn freely without binding.
k) If a cartridge seal is fitted, reset it at this point.
l)
Ensure the coupling distance between shaft ends
(DBSE) is correct. Reset/re-align if necessary.
6.7.2 Setting open impeller
For the Mark 3 open (OP) impeller the rear clearance
setting is as shown in the table below.
Temperature
Impeller clearance setting
(RV and OP impeller)
All impeller diameters
50 ºC (120 ºF)
100 ºC (210 ºF)
150 ºC (300 ºF)
200 ºC (390 ºF)
260 ºC (500 ºF)
0.45 mm (0.018 in.)
0.55 mm (0.022 in.)
0.65 mm (0.026 in.)
0.75 mm (0.030 in.)
0.85 mm (0.033 in.)
a) Before carrying out this procedure on the CPXV
ensure that any mechanical seal(s) fitted can
tolerate a change in its axial setting, otherwise it
will be necessary to dismantle the unit and reset
the seal axial position after adjusting the impeller
clearance.
b) Disconnect the coupling if it has limited axial
flexibility.
c) Record the gap between the bearing carrier [3240]
and stool [3160] using feeler gauges.
Some mechanical seal types may be
impaired if moved more than 0.5 mm (0.02 in.)
from their nominal setting.
d) Loosen the bearing carrier screws [6570.8] and
slacken off the bearing carrier using screws [6570.7].
e) Ensure the carrier jacking screws [6570.7] are
slackened off evenly so as to draw the bearing
carrier towards the sole plate, until the impeller just
contacts the pump casing. Turn the shaft [2100]
during this procedure until a detectable rub is
obtained. This is the zero clearance position. The
shaft must be turned in the direction indicated on
the casing and sole plate.
f) Set a dial indicator to zero on the shaft end or
measure the bearing carrier [3240] to motor
pedestal [3160] gap and record the measurement.
g) Ensure carrier screws [6570.8] are still slack and
tighten the bearing carrier jacking screws [6570.7]
evenly (about one flat at a time) until the dial
indicator or feeler gauge shows the correct impeller
clearance from the zero clearance position. This
clearance should be between 0.45 and 0.85 mm
(0.018 and 0.033 in.) depending on the temperature
of the pumped fluid, as in the table above.
h) Evenly tighten the bearing carrier screws [6570.8]
keeping the dial indicator or feeler gauges reading
the correct setting. Then tighten the hexagon nuts
[6580.5] to lock the jacking screws [6570.7] in
position.
i) Compare the original and final gaps between the
bearing carrier and sole plate to check if the
movement of the shaft has exceeded the
mechanical seal capability (over/under compression
of the seal). Re-position the seal to correct this.
j) Check that the shaft can turn freely without binding.
k) If a cartridge seal is fitted, reset it at this point.
l)
Ensure the coupling distance between shaft ends
(DBSE) is correct. Reset/re-align if necessary.
6.8 Renewal clearances
As wear takes place between the impeller and casing
ring the overall efficiency of the pump set will
decrease. To maintain optimum efficiency it is
recommended that the clearances shown in section
6.7, Setting impeller clearance, are maintained.
On product lubricated bearings it is recommended
that these are renewed at the diametrical clearance in
the as fitted condition stated in the following table:
Bearing sleeve size
mm (in.)
Sleeve
diameter/tolerance
min diam - max diam
mm (in.)
Bearing clearance
(max/min)
mm (in.)
Fr1/2 silicon carbide
54 (2.125)
53.87
(2.1209)
53.89
(2.1217)
0.13/0.085
(0.0051/0.0033)
Fr3/4 silicon carbide
79 (3.110)
78.85
(3.1043)
78.87
(3.1051)
0.18/0.13
(0.0071/0.0051)
Fr1 pump end bush in
engineering polymer
35 (1.375)
34.98
(1.3772)
35.00
(1.3780)
0.31/0.15
(0.0122/0.0059)
Fr1 intermediate and Fr2
pump end bushes in
engineering polymer
45 (1.770)
44.98
(1.7709)
45.00
(1.7717)
0.35/0.19
(0.0138/0.0075)
Fr3 pump end bush in
engineering polymer
65 (2.559)
64.98
(2.5583)
65.00
(2.5591)
0.41/0.25
(0.0161/0.0098)
Fr2/3 intermediate
bushes in engineering
polymer
65 (2.559)
64.98
(2.5583)
65.00
(2.5591)
0.39/0.23
(0.0154/0.0091)
Fr4 pump end and
intermediate bush in
engineering polymer
70 (2.7559)
69.98
(2.5583)
70.00
(2.7559)
0.39/0.23
(0.0154/0.0091)