Pulling a deep vacuum on a system to remove air, moisture and non-condensables before charging.
Evacuation lowers the pressure inside a system far enough that moisture boils away and air is removed. It follows repair and pressure testing and comes before charging.
Speed and accuracy come from setup: remove valve cores with a core tool, use short, large-diameter hoses, and read a micron gauge at the system. Confirm the result with a decay test. Sub-task B-7.03 of the Red Seal task matrix, "Evacuates systems", covers this work.
Exam work areas
B · Tools, piping and refrigerant handling