11
STACK ASSEMBLY SEQUENCE
Step 1. Clamp the fixture in the vise and
insert the shaft. Pin the shaft with the lock
spindle inserted in the “ASSEMBLY” hole.
Step 2. Add the first impeller. Tap the collet
into the impeller hub with the collet driver
until it locks to the shaft and the impeller is
seated on the fixture.
Step 3. Apply anti-seize oil to the impeller
threads, add the locknut; hold the impeller
with the wrench and tighten the locknut
against the collet. Torque to 52 ft.-lbs.
1
2
3
1st Stage Will Be:
1-Stage Pump:
Type F (Step 9)
All Others:
Type D
Add Bearing
only on 3-Stage
Pumps (type DB
Stage)
Locknut
Collet
2nd Stage Will Be:
2-Stage Pump: Type F (Step 9)
3-Stage Pump: Type DB
All Others: Type D
Step 4. Remove the lock spindle. Remove
the shaft from the fixture, seat the bottom
flange in the fixture, and reinsert the shaft/
impeller assembly into the fixture. Reinsert
the lock spindle from the opposite side of
the fixture (that is, in the hole in the fixture).
For single stage pumps, skip to Step 9.
Step 5. Slide a bowl (see Figure 8) down the
shaft until it seats on the bottom plate.
Step 6. Slide the next impeller, collet, and
locknut down the shaft and repeat Steps 2
and 3. For two-stage pumps, skip now to
Step 9. For three-stage pumps, add a bearing
(type DB stage) before going to Step 7.
Step 10. Check for free rotation. If the
stack now rotates freely, it is ready for
installation in the pump.
Step 7. For all pumps with more than three
stages, use a type D stage. Three-stage
pumps use type DB (with spacer over the
locknut) and go to Step 9. NOTE: If your
pump has reduced diameter impellers (for
example, a PVM32-6-2), they go in the
top stages. In a PVM32-6-2, for instance,
stages 5 and 6 (the top two) are reduced
diameter. Note that the impeller shroud is
full diameter; only the vanes are reduced.
Be sure you do not mix them with full
diameter impellers.
Step 8. Repeat Steps 5 and 6, following the
order for bowl assembly shown in Figure 8.
Repeat until you have done the next to the
last bowl, then go to Step 9.
Step 9. Add type F stage bowl (with cutouts
for straps). Insert the straps in the holes
in the bottom plate, hook into the bowl
cutouts, add nuts and washers, and tighten
the straps to 4.4 ft.-lbs. (53 in.-lbs.) of
torque (see Table IV).