We introduced the 3-piece screw design both as a conversion kit for existing
pumps and also as the standard for all new Type M pumps sold. This design splits
the pump screw into three sections which are bolted together at the balance
wheels of the screw.
On each end there is a stub shaft which is contained inside the bearing housing
assembly. The center screw section is the replaceable wear part. It is no longer
necessary to disconnect the coupling, expose the bearings and seals to a dusty
and dirty plant environment, and pry the screw out of the drive side bearings.
Furthermore, the 3-piece design requires the manipulation of fewer bolted
connections compared to the 1-piece design - about 1/3 less.
Field data has shown that a screw change out can be accomplished with two
technicians in 3-4 hours, while it may take three technicians and 6-8 hours for the
one-piece screw design. There is no need to disconnect the motor from the drive end.