Upgrades, modifications, and rehabilitation of existing pump stations can be categorized as:

  • In-Kind Pump Replacement
  • Modified Capacity Replacement.

In-Kind Pump Replacement

An in-kind pump replacement matches the pump type, suction diameter, rotating speed, head and flow to  provide the same performance, reliability, and longevity as the pump it replaced.

If historical performance is acceptable, an in-kind replacement is often a reasonable approach, even in situations where the piping does not meet the piping standards.

If the historical performance is unacceptable, the suction piping should be evaluated to determine if intake conditions are the source of the problem.

Modified Capacity Replacement

System changes can alter the operating conditions such that the existing pump is no longer suitable for the application. Inline flow straightening spools can improve the approach flow into the pump helping to resolve these issues.

Inline flow straightening spool with grating installed into a custom pipe spool

Purpose: Grating can be used in the piping approaching a pump to reduce suction energy and stabilize the flow.

Design: Grating may have a depth-to-opening ratio that varies from 1:1 to 3:1, depending on application.

 

Typical grating configuration:

NOTE: Head loss through the grating should be nominal; however, it is important to evaluate head loss, especially for systems with limited NPSH available.