We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Required Level of Evacuation of Appliances

This table lists levels of evacuation for various types of refrigeration and air conditioning equipment manufactured either before or after November 15, 1993.

Type of Appliance Inches of Hg vacuum
(relative to standard atmospheric pressure of 29.9 inches Hg)
  Using pre-1993 equipment Using post-1993 equipment
Very high-pressure appliance 0 0
High-pressure appliance, or isolated component of such appliance, with a full charge of less than 200 pounds of refrigerant 0 0
High-pressure appliance, or isolated component of such appliance, with a full charge of 200 pounds or more of refrigerant 4 10
Medium-pressure appliance, or isolated component of such appliance, with a full charge of less than 200 pounds of refrigerant 4 10
Medium-pressure appliance, or isolated component of such appliance, with a full charge of 200 pounds or more of refrigerant 4 10
Low-pressure appliance 25 mm Hg absolute 25 mm Hg absolute