
New 3200-406
Oct., 2009
Cornell Pump Company
How to Disassemble and Reassemble a Cornell
Solids Handling Pump with Threaded Shaft and Cycloseal TM
Some parts mentioned in these instructions may not apply to your pump. Refer to your specific parts page for part
names.
DISASSEMBLE
1. Remove all capscrews holding volute to backplate. Insert two of these capscrews into tapped holes in backplate.
Tighten capscrews to jack the volute free of the backplate exposing the impeller. Remove volute. Make sure volute
does not fall onto impeller.
2. Remove impeller lockscrew by breaker bar not by impact wrench. Make sure to apply steady and even torque to
break lockscrew loose. Allen head tooling to remove lockscrew should be in excellent condition. Discard lockscrew,
under emergency conditions this may not be possible. New lockscrew should be used when possible. Remove the
impeller washer.
3. Impeller threads can be right or left hand depending on the rotation of the pump. There will be right hand threads on a
right hand rotation pump, and likewise, left hand threads on a left hand rotation pump. To remove impeller, attach a
flat bar to the drive hub or coupling flange on the drive end of the shaft. (See page 3200-401). Looking from the
impeller end, have the lever rest on the table or floor opposite the direction of rotation. Hold impeller firmly and lift
lever, then rapidly reverse and ram the lever onto table or floor. Repeat this operation until the impeller thread
unlocks. If this method does not unlock the impeller use an impeller pry-bar (see 3200-401). With the flat bar-drive
hub used in the previous method, unscrew and remove impeller.
4. Remove mechanical seal (at this point, it is probably easier to leave the stationary seat in the backplate until the
backplate is removed). If you elect to remove the seat now, use extreme care or it will break (fragile).
5. Unbolt and remove backplate from bracket. If the stationary seat has not been removed yet, use extreme care when
sliding backplate along shaft to avoid chipping of the mechanical seal seat on the shaft. If the seal is being replaced,
carefully remove the stationary seat from the backplate.
6. Remove sleeve only if necessary. Install sleeve puller over the outside diameter of sleeve and lock puller to sleeve
with set screws. Remove puller and sleeve with standard gear puller. If the parts page shows an O-ring in the sleeve,
the sleeve can be pulled off.
7. The suction wear ring can be removed by drilling the ring longitudinally in three places to relieve
compression and collapsing the three sections together. Use care not to drill into the volute casting. Better
control is obtained if small pilot holes are first drilled and then enlarged to “cut” the ring.
REASSEMBLE
1. To install sleeve, heat new sleeve very uniformly to about 4000for about 10 minutes. Slide it on the shaft quickly.
However, if sleeve has an O-ring, it should not be heated. Remove burrs on shaft around keyway before
replacing sleeve.
2. Install backplate.
3. Install mechanical seal. See seal installation instructions.
4. Use shims provided by the factory to obtain .030” clearance (preferred tolerance is ± .003”, get as close to .030” as
you can) between impeller backvanes and backplate. Shims will be sandwiched between impeller hub and thrust
washer. This does not apply to models 12NHTL and 12NHTM for which the clearance between impeller and
backplate is very large.