Liquid slugging and floodback: how the compressor is at risk

The compressor is designed to compress vapor and not liquid refrigerant.

Floodback

Refers to the return of an excessive amount of liquid refrigerant to the compressor during operation.

Liquid slugging

This is a more severe phenomenon where liquid enters the compressor and can cause mechanical damage.

Potential causes

Very low superheat, a faulty expansion valve, or unsuitable operating transition conditions.