Pumps designed for suction lift conditions typically use what kind of stuffing box?

Pumps designed for suction lift conditions typically utilize a sealing or injection type stuffing box because this design is specifically aimed at preventing air from entering the pump casing. When a pump operates under suction lift, it relies on creating a vacuum to draw fluid into the pump. Any air leakage or loss of prime can significantly affect the pump's performance and efficiency.

The sealing or injection type stuffing box is equipped to manage the potential for air ingress by incorporating a means of injecting sealing liquids or maintaining appropriate fluid levels around the shaft. This allows for better lubrication and sealing, creating a barrier against air leaks while ensuring that the potential for cavitation or vapor binding is minimized. This is particularly critical in applications where the pump must maintain a consistent and reliable function under conditions of fluctuating pressures or levels.

In contrast, other stuffing box types, while they may serve specific applications well, do not provide the same level of control over potential air leaks that a sealing or injection type does, making it the most suitable choice for suction lift scenarios.