What are the two basic types of pump shaft seals?

The two basic types of pump shaft seals are mechanical seals and compression packing. Mechanical seals are designed to provide a tight seal at the rotating shaft of the pump, preventing leaks of the pumped fluid. They consist of two primary components: a rotating part attached to the shaft and a stationary part mounted on the pump housing. The interface where these components meet is where the sealing occurs under pressure, which can effectively manage various fluid types and pressures.

On the other hand, compression packing is a method that uses a braided material, typically made from various types of fibers or other materials, that is compressed into a stuffing box around the shaft. This type of sealing is more traditional and can accommodate shaft movement and wear over time, although it may require periodic adjustment or replacement to maintain effectiveness.

Understanding these two types allows one to choose the appropriate sealing method based on the specific application, fluid type, and operational conditions encountered in refrigeration and pump operations. Other options like ball and roller bearings, gaskets and o-rings, and threaded and welded seals do not primarily focus on the sealing of rotating shafts in pumps.