FRBH, FRBHX AND FRBHS USER INSTRUCTIONS ENGLISH 71569178 20-08
Page 42 of 60
Flowserve.com
®
maintain the impeller axial clearance as detailed in
section 3.5, Table of Engineering Data. Typically
doubling the clearance can reduce performance by
5% depending on pump size and operating condition.
6.8
Disassembly
Refer to section 1.6,
Safety
, before dismantling
the pump.
Before dismantling the pump for
overhaul, ensure genuine Flowserve replacement
parts are available.
To disassemble the pump, consult the sectional
drawings, s
ee section 8,
Parts list and drawings
.
6.8.1
Rotor unit
The following procedure is recommended for removing
and disassembling the back pull-out element (rotating
assembly).
Note that the replacement gaskets and similar
consumable materials should be available since they will
be required for reassembly.
a) Isolate motor and lock off electrical supply in
accordance with local regulations.
b) Isolate suction and discharge valves.
c)
Remove coupling guards and disconnect the
coupling halves.
d)
Drain pump casing. Remove any auxiliary piping
if applicable.
e)
Disconnect stuffing box, cooling water and auxiliary
piping
.
f)
Drain the oil from the bearing bracket [3130] if
bearing frame is being dismantled.
g) Place the sling around the bearing bracket [3130]
and carefully take up the weight without straining the
casing. Refer to Section 3 to determine hoist and
sling requirements.
h) Loosen the set screws holding the deflector [2540]
on the shaft.
i) Release the thrust bearing bracket [3230] hold down
bolts and jam nuts. While rotating the pump shaft
[2110] by hand, tighten the three jacking screws
evenly until the impeller [2200] lightly clamps the
stuffing box head [4100] in place. In the case of
expeller pumps the same will hold for the housing
[4110]. This will simplify withdrawal of the rotating
element from the casing.
Excessive clamping force could
damage bearing races.
Rotating the shaft helps to clear away solids which
may be trapped between the impeller and stuffing
box head.
j) Remove the bolts connecting the rear support foot
[3134] to the baseplate.
k) Remove the frame to casing bolts
l) Withdraw the rotating element from the casing.
For FRBHS designs, there is a loose
adapter [1340] that spaces the bearing bracket [3130]
from the pump casing [1110]. This item may stay lodged
within the casing or could be removed with the rotating
element. Once the rotating element is removed locate
this item and remove it to a safe location.
6.8.2
Stuffing box
6.8.2.1
Shaft seal - gland packing
a) Remove gland nuts and gland halves [4121]
b) Lever out gland ring [4130] using its grip groove.
c) Remove gland packing rings [4130] and lantern
rings [4134] using a bent wire.
6.8.2.2
Shaft seal - mechanical seal
Refer to any special instructions supplied with
the mechanical seal.
a)
Remove seal cover screws and pull off seal cover
complete with the stationary seal ring which is held
in place by the O
-
ring seal.
b)
The mechanical seal cover can also be removed by
placing a wedge into the gland chamfer, as below:
6.8.2.3
Impeller and stuffing box
a) While preventing the shaft from rotating, remove the
impeller nut [2912] that has a right hand thread.
b) Remove the impeller [2200] and impeller key [6700].
Normally, a slight tightening of the thrust gearing
jacking screws will free the impeller and allow it to be
removed. Except on the smaller sizes, there is a
facility on the impeller hub to assist removal in
difficult cases.
c) Remove the expeller housing [4110] & radial impeller
[2250] and/or stuffing box head [4100] as applicable
to pump construction.
6.8.3
Shaft sleeve
a) Remove the shaft sleeve gasket [4590].
b) Remove the shaft sleeve [2445] if scored or worn.
6.8.4
Bearing housing
a) Remove the deflector [2540] and the line bearing
cover.
b) Remove the pump half coupling and coupling key
[6700].
c) Remove the support foot [3134].
d) Lift the bearing frame assembly into a vertical
position with the thrust bearing housing [3230] up.
Rest the bearing frame flange on heavy wooden
blocks sufficiently high to ensure end of the shaft
does not come into contact with the floor or table.
e) Remove the thrust bearing hold down bolts and
