When recovering refrigerant, how long should a technician wait to check for residual pressure?

When recovering refrigerant, waiting for 5 minutes before checking for residual pressure is the recommended practice. This timeframe allows enough time for the refrigerant to circulate within the recovery system and for any transient pressures caused by changes in temperature to stabilize.

During the recovery process, refrigerant can be affected by various factors, including temperature fluctuations and the operational state of the recovery equipment. A brief wait ensures that the technician obtains an accurate reading of the pressure. If a technician checks too soon, they may receive a misleading pressure reading that does not accurately reflect the actual residual pressure in the system, potentially leading to improper service decisions.

Allowing 5 minutes provides a balance; it is long enough to let the pressures stabilize but not so long that it significantly delays the recovery process. This practice also helps ensure compliance with safety standards when working with refrigerants, as understanding residual pressures is crucial for effective and safe handling of these substances.