When refrigerant recovery from a system using R-11 or R-123 begins, what is the first step?

The first step in recovering refrigerant from a system using R-11 or R-123 is liquid removal. This is crucial because refrigerants can exist in both vapor and liquid phases, and to ensure safe and efficient recovery, it is important to remove the liquid refrigerant first.

Liquid removal helps to avoid potential issues that can arise from vapor recovery, such as compressor damage or inefficient recovery processes. By starting with liquid removal, the technician can effectively take advantage of the refrigerant's properties and maximize the recovery process, ensuring that the majority of the refrigerant is captured before switching to vapor recovery. Additionally, handling the liquid refrigerant reduces the volume of vapor that would otherwise need to be managed, making the process more efficient and compliant with safety regulations.

Starting with the removal of liquid refrigerant also aligns with industry best practices and manufacturer recommendations, which prioritize safety when dealing with volatile substances such as R-11 and R-123.