Final answer:
The minimum pressure for refrigerant recovery in a refrigeration system varies and is typically specified by the manufacturer or regulations, measured using a gauge, and ensures safe, effective recovery without damage to equipment or environmental harm.
Step-by-step explanation:
The minimum pressure for recovering refrigerant in a refrigeration system is typically specified by the manufacturer or local regulations. It's important to ensure that the system has sufficient pressure before attempting recovery to avoid damage to the equipment or the release of refrigerant into the atmosphere. The pressure is measured using a gauge that displays readings in pounds per square inch gauge (psig). The exact pressure level can vary, but it is commonly set to prevent the recovery of refrigerants when the system pressure is too low, which could indicate a nearly empty system or one that has non-condensable gases.