Which option best describes the role of a surge drum in a flooded system?

A surge drum in a flooded system primarily serves the purpose of separating vapor from liquid refrigerant. This is a critical function because it ensures that only vaporized refrigerant is sent to the compressor, maintaining the efficiency and safety of the refrigeration system. In a flooded system, where liquid refrigerant is present, the surge drum collects the liquid refrigerant and allows it to settle, enabling the less dense vapor to rise to the top. This separation is essential because introducing liquid refrigerant into the compressor can lead to compressor damage through hydraulic shock or slugging.

This role is particularly important in maintaining system balance and optimizing performance, as it prevents liquid carryover into the compressor and helps in the effective circulation of refrigerant throughout the system. By ensuring that the vapor returned to the compressor is free from liquid, the surge drum contributes to the overall reliability and efficiency of the system.