Flowserve Twin Screw Rotary - Manual (Page 43)

TWIN SCREW PUMPS. ORIGINAL USER INSTRUCTIONS. ENGLISH. 71569243 – 07/10
Page 40 of 53
®
cartridge type) mechanical seals the seal
rotating heads [4200.1] must also be mounted
on the shafts prior to this operation. If a new
rotating element is being installed do not
install the seals at this time. Refer to the NEW
ROTATING ELEMENT section of this book.
f) Replace the rear bracket to body capscrews
and finger tighten only at this point.
g) Mount the rear bearings [3011] onto the shaft
and into the rear bracket.
h) Fit the bearing lockwashers [6540.1] and
locknuts [5260.1]. Tighten the locknuts
securely but avoid overtightening as the
lockwasher tab could be damaged. Bend over
one tab on each nut to lock in place.
i) Replace the rear caps [3510] and gasket/O
rings [4610]. If the pump has individual rear
caps check that the insertion length of the cap
is greater than the recess depth by .001/.002”
to ensure the cap contacts the bearing outer
race. Mount a new end flange gasket [4590]
on the front end of the pump body.
j) Install new front bearing inner races (on the
shafts. See Step o) below for instructions.
Mount the front bracket [6160.1] onto the body
with oil seals [4310.2] and bearings [3012] in
place noting the precautions in Step e).
k) Replace the front bracket to body capscrews
and finger tighten only.
l) Line up dowel pin holes in the front and rear
brackets and insert the dowel pins [6810.3].
Tighten all capscrews and nuts.
m) Mount timing gears [2810] and spacers
[2164.1, 2164.2, 2164.3] onto shafts in the
exact location from which they were removed.
Tighten locknuts noting the precautions in
Step h). Note the pump should now turn
freely. If it doesn’t refer to Free Movement
Section 6.11 of this manual.
n) Use an induction heater or hot oil bath to heat
the bearing race to 200 deg F (recommended)
and install the bearing race on the shaft and
against the locating shoulder.
o) Mount a new gasket [4590] on the front
bracket flange.
p) Mount the gear housing [1600], with bearings
[3014] and lip seal [4310.2] in place, onto the
front bracket.
q) Line up the dowel pin holes (if equipped) in
gear housing and bracket flanges and insert
dowel pins. Check that pump still turns freely.
r) Repack the stuffing boxes with new packing.
6.9.3
Reassembly of internal bearing pump
a) Inspect all new parts. Remove all nicks and burrs
which may have occurred in handling.
b) Install the timing gears [2810] complete with keys
[6711], lockwashers [6540.2] and locknuts onto
the correct shafts.
c) Install the inner race on the shaft. Use an
induction heater or hot oil bath to first heat the
race. (90
° C (200° F) recommended). Press the
inner race on the shaft with the aid of a sleeve so
that it remains square to the shaft.
d) Intermesh the drive [2120] and driven [2140]
shafts, taking care to align the timing marks on the
face of the timing gears. Slide the shaft assembly
into the body.
e) Install the thrust bearings [3011] in the rear head
[3717.2].
f) Mount a new end flange gasket [4590] on the rear
of the body [1110].
g) Slide the rear head assembly over the shafts and
mount on the end of the body. (Note that the “top”
mark is in the correct location. If a new rotating
element is being installed in the pump, refer to
section 6.10.1.2 Internal bearing pump.
h) Mount a new gasket on the rear head and fit the
rear cap [3510.1]. Replace all capscrews in the
rear end finger tight only.
i) Install the front bearing outer race assemblies
[3014] into the front head [3717.1].
j) Mount a new gasket [4590.1] on the front of the
body and slide the front head into place, noting
the position of the “top” mark.
k) If the pump is fitted with a mechanical seal (non
cartridge type), mount the rotating head on the
drive shaft using the mark scribed at disassembly
for location. Tighten all set screws securely.
l) Re-fit all alignment dowel pins [6585].
m) Tighten all capscrews at rear end of pump.
n) While tightening all capscrews at the front of the
pump, rotate the drive shaft by hand to check for
binding. If the pump binds before the capscrews
are tight refer to Section 6.11
o) Install the seal stationary seat in the seal gland
and install the gland on the front head.
p) If the pump has a packed stuffing box, install new
packing and replace gland.
q) Replace bearing lubrication lines and/or other
auxiliary piping.
6.10 New Rotating Elements
6.10.1 Mechanical seal (non cartridge type) fitted
pumps
6.10.1.1 External bearing pump
If a new rotating element is being installed, the pump
should be assembled without mechanical seals up to