If a refrigeration system operates under critical pressure, what should be noted regarding pressure testing?

When a refrigeration system operates under critical pressure, it is essential to ensure that the testing mechanisms do not exceed the saturation pressure of the refrigerant. This is because the saturation pressure is the pressure at which the refrigerant changes phase from liquid to vapor. If the testing pressure exceeds this point, it can lead to unwanted phase changes and potentially hazardous conditions, including equipment failure or a safety risk for those working on or around the system.

Maintaining pressure at or below the saturation pressure is crucial for both safety and system integrity. It allows for proper functionality and reliability of the refrigeration system without the risk of causing complications that arise from excessive pressure. By adhering to this guideline, technicians can ensure that the system operates safely while under testing conditions and subsequently during regular operation.