In a low-pressure system, when removing refrigerant by vapor, which items should be confirmed to be operating?

• A. The system water pumps, the recovery compressor, and the recovery condenser water
• B. Only the recovery compressor
• C. Only the condenser water pump
• D. All devices off

Answer: (A)

When removing refrigerant by vapor in a low‑pressure system, you must have the equipment that handles compression and heat rejection working, because the vapor must be compressed and then condensed so it can be recovered safely. The recovery compressor moves the refrigerant vapor, and the recovery condenser needs circulating cooling water to reject heat from that compressed vapor so it can condense back to liquid. The system water pumps are essential to keep that cooling water flowing to the condenser (and any other heat exchangers involved). If any one of these parts isn’t operating, condensation won’t occur efficiently, pressures can rise, and recovery will be unsafe or ineffective. That’s why the best option is to ensure the system water pumps, the recovery compressor, and the recovery condenser water are all operating.