TECH TIPS

Over the last fifteen years, adding a pump to the liquid line of a refrigeration system has become an increasingly common practice. Once employed primarily in ammonia systems, refrigerant pumping is now being used in applications like supermarket rack systems and split system air conditioning units. By installing a pump in these systems, users typically hope to enhance the flow of refrigerant.

Regardless of the desired benefit, a pump can only be expected to perform one function: to add a finite amount of pressure at its outlet. For this to happen, however, the installation procedure is critical. If the pump is a centrifugal type, care must be taken to minimize the amount of vapor at the inlet. If the pump is a positive displacement type, care must be taken to prevent overpressurizing the system.