Pumps are divided into three basic categories: centrifugal, rotary, and reciprocating. Take any of the three types and break it down further into four parts, the rotating element, the casing, the motor, and the drive.

• The rotating element has the shaft, sleeves, bearings and impeller.
• The casing has the pump shell, wear rings, and shaft seals.
• The motor and drive are intuitive.

Here is a basic remediation list:

1.) Belts are slipping (if applicable)

2.) Impeller worn

3.) Impeller loose on shaft or shaft sheared

4.) Casing worn

5.) Original motor was replaced with a slower model or with greater amount of motor slip

6.) Requirements have changed beyond the design specifications of the system. Verify that you have a speed problem with a manual tachometer.

If all of the above have been investigated, then a fix could be to increase the maximum frequency of the drive. Understand that anything beyond 60 Hz will result in a shift from a constant torque to a variable torque situation. There is a low probability that the drive will affect the intrinsic speed of the system detrimentally.