A centrifugal pump with high suction lift and negative casing pressure is likely to have what feature?

A centrifugal pump operating under high suction lift and negative casing pressure is particularly susceptible to issues such as cavitation and air ingress. The presence of a lantern ring or seal cage in the stuffing box becomes crucial in this context.

The lantern ring serves to provide a means of maintaining a consistent supply of lubrication to the packing, which is important for extending the packing’s life and ensuring proper sealing. In conditions where the pump may be operating under negative pressure, this allows for better management of the sealing materials and helps to minimize the risk of leaks or cavitation due to air entering the system. The effectiveness of the lantern ring in maintaining liquid at the packing also helps to reduce wear caused by the dry running that can occur when negative pressure exists.

Thus, the inclusion of a lantern ring or seal cage effectively addresses the operational challenges posed by high suction lift and negative casing pressure, making it a key feature for ensuring that the pump operates efficiently and reliably under these conditions.