Pag. 36/49
Doc. ISM0076_MANUALE_CN SEAL-MV_ENG_REV04.DOCX
g) Unscrew cap screws that hold bearing housing (32) to casing cover (9) and tap casing cover and
bearing housing with mallet to break cover loose from housing.
The impeller cap nut (20) is left hand threaded. To remove the impeller cap nut, turn it to the right
(clockwise) while facing the impeller.
h) Hold shaft sleeve in place and carefully slide casing cover (9) with sleeve and mechanical seal parts
off shaft and clear of bearing housing (32).
The stuffing box bushing (10) is pressed into the casing cover (9) and should not be removed unless
worn or badly scratched or gouged, in which case the old bushing must be pressed out and a new one
pressed in.
i) Set casing cover (9) on workbench with bearing-housing side up.
To disassemble a mechanical seal follow the seal manufacturer's instructions in the Appendix.
j) Remove the seal plate nuts and the mechanical seal (21).
k) If no pumpage has got into bearing housing and you plan to replace just the mechanical seal, omit the
remaining steps; otherwise continue to disassemble pump as outlined.
l) Evenly heat pump half-coupling using a welding torch with a Rosebud head until you are able to pull
half-coupling off with a coupling puller, then remove half-coupling and key (18.1).
m) Remove outboard fan (28.1) and O-rings (27.1). Loosen screw on inboard fan (28.2) and slide off
shaft.
n) Unscrew bearing housing end cover cap screws (29.1) and slide it off shaft, with the labyrinth seal
(5), remove the O-ring (27.1).
Now it is possible to extract bearing labyrinth seal (5) and replace it in case of worn or damage.
CAUTION
Although not necessary, it may be worthwhile to lift the bearing housing and block
it in a vertical position with the thrust bearing up to facilitate removal of the shaft
and bearings. Support shaft as it is moved out of bearing housing by soft cables and
hoist or wood blocks.
p) Remove shaft (12), with thrust bearings (15) and radial bearing (14) installed, from bearing housing
(32).
q) Proceed as follows:
• If your pump is grease or pure mist lubricated, then slide the labyrinth seal (29.1) and O-ring (27.2) off
of the shaft (12).
• If your pump is oil lubricated, then loosen the set screws which hold the screw pump to the shaft, then
slide the screw pump (30) off of the shaft.
r) Place shaft in a vice which is covered with a soft material such as copper to prevent marring; then
clamp it just enough to keep it from turning when thrust bearing lock nut (26) is broken loose.
s) Bend back tab on thrust bearing lock washer (25). Unscrew thrust bearing lock nut (26).
