Type II Evacuation Levels
For high-pressure equipment using post-November 15, 1993 recovery equipment: systems with less than 200 lbs of refrigerant must be evacuated to 0 psig, and systems with 200 lbs or more must be evacuated to 10 inches Hg vacuum. Proper evacuation removes moisture and non-condensable gases. A vacuum pump pulls the system below atmospheric pressure, lowering the boiling point of any trapped moisture so it vaporizes and is removed. Always use a micron gauge for precise vacuum measurement.
Post-1993 equipment: <200 lbs evacuate to 0 psig; >=200 lbs evacuate to 10 in. Hg vacuum.
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