Goulds Pumps 3420 - IOM - Manual (Page 74)

REASSEMBLY
1. Determine the correct positioning of the impeller
(101) on the shaft (122) based on the direction of
rotation. Refer to Figure 55.
2. Insert the impeller key (178) in the shaft and slide the
impeller on the shaft. Drive or press the shaft into the
impeller.
$
CAUTION
Do not damage the end of the shaft.
Line up the impeller hub with the scribe mark made on the
shaft during disassembly. If a new shaft is being used,
center the impeller on the keyway.
3. Place the impeller O-rings (412A) in the grooves in
the end of the sleeves (126). Slide the shaft sleeves on
the shaft.
4. Place the sleeve O-rings (497) in the grooves in the
end of the sleeve nuts (124 and 130). Slide the sleeve
nuts on the shaft. Tighten the nuts against shaft
rotation using a spanner or strap wrench.
NOTE: One sleeve has right hand threads and one has
left hand threads. The nuts tighten against the pump’s
rotation.
5. Tighten the set screws (222B) in the sleeve nuts.
6. Packing: Slide the stuffing box bushings (125) over
the sleeves. Position them such that the lock is facing
the packing. Slide the lantern ring (105) on the shaft.
Conventional Mechanical Seals: Carefully slide the
rotary portion on the sleeve and fasten in position
according to the manufacturer’s instructions.
Carefully slide the seal glands with the stationary seats
and the gland gaskets on the shaft.
Cartridge Mechanical Seal: Carefully slide the
cartridge unit on the sleeve.
INSTALLATION OF THE BEARING
HOUSINGS AND BEARINGS
A. SX/MX Group
1. Press the inboard labyrinth seals (333A) into the end
covers (109) with a suitably sized arbor. Slide the end
covers with the seals installed onto the shaft (122) up
to the sleeve nuts (130). The labyrinth seals should
face the sleeve nuts as shown in Fugures 29-32.
2. Install the radial (coupling end) bearing (168) on the
shaft.
NOTE: There are several ways to install bearings.
The recommended method is to use an induction
heater that heats as well as demagnitizes the bearings.
s
! WARNING
Wear insulated gloves when using a bearing heater.
The bearings will get hot and can cause physical
injury.
NOTE: Coat internal surfaces of bearings with the
lubricant that is to be used in service.
3. Install the thrust bearing (112) on the shaft.
NOTE: The SX and MX groups use duplex bearings
mounted back to back. Make sure the orientation is
correct.
NOTE: There are several ways to install bearings.
The recommended method is to use an induction
heater that heats as well as demagnitizes the bearings.
s
! WARNING
Wear insulated gloves when using a bearing heater.
The bearings will get hot and can cause physical
injury.
NOTE: Coat internal surfaces of bearings with the
lubricant that is to be used in service.
4. Place the bearing lockwasher (382) on the shaft. Be
sure to place the tang of the lockwasher in the keyway
of the shaft.
5. Thread the bearing locknut (136) onto the shaft. After
the bearing and the shaft have cooled to ambient
temperature, tighten the locknut to the value shown in
Table 11. Bend any tang of the lockwasher into a slot
in the locknut.
6. Press the outboard labyrinth seal (332A) into the
radial (coupling end) bearing housing (166) with a
suitably sized arbor. Install the radial (coupling end)
70
3420 IOM 8/09
Fig. 55