Protecting centrifugal pumps at low flow

Centrifugal pumps which operate under variable flow rates often require protection against prolonged operation at low flow rates. Determining the flow rate at which protection is required and the type of protection required is as important as the actual provision of low flow protection. This discussion deals with the correct application of low flow protection of centrifugal pumps and does not address the determination of the flow rate below which low flow protection is required.