Checking a refrigeration circuit for leaks, usually by pressurizing with dry nitrogen.
A standing pressure test uses dry nitrogen through a regulator, at or below the test pressure on the equipment nameplate. Let the pressure settle and correct for temperature before judging a drop. Electronic detectors, bubble solution and ultrasonic detectors locate a leak once you know there is one. Never pressurize a system with oxygen or shop air, and never charge refrigerant just to find a leak.
Exam work areas
B · Tools, piping and refrigerant handling