The role of the mechanical shaft seal is primarily to:

The role of the mechanical shaft seal is primarily to prevent refrigerant leakage. This is crucial in an ammonia refrigeration system because ammonia is a toxic and potentially hazardous substance. By ensuring that the refrigerant does not leak from the compressor, the mechanical shaft seal helps maintain system efficiency, safety, and environmental compliance.

The design of the mechanical shaft seal is specifically intended to create a barrier that maintains the integrity of the refrigeration system while allowing the motor shaft to rotate. In doing so, it effectively keeps the refrigerant contained within the compressor and prevents escape into the surrounding environment.

Other possible roles of components in the system, such as enhancing cooling capacity or supporting compressor stability, are important but not the primary function of the mechanical shaft seal. The efficiency of the compressor may be indirectly influenced by the effectiveness of the seal, but it is not the seal's main purpose.