During the operation of refrigeration equipment, especially when compressors and refrigerants experience leaks, it severely affects the cooling performance. Generally, when refrigeration equipment is under vacuum for a certain period, the change in the reading of the vacuum pressure gauge can reflect if air has渗入. So, how should one proceed? The refrigeration equipment manufacturer will guide you on how to check the air tightness of refrigeration equipment.
 
Vacuum Leak Detection

Counter-clockwise, unscrew the fine-threaded plug on the suction cutoff valve's passage. Rotate the suction cutoff valve handle clockwise several times to place the valve in the tee position. Connect the vacuum pump to the multi-port interface on the suction cutoff valve using a flexible hose equipped with a tee repair valve and a vacuum pressure gauge; open all valves within the refrigeration equipment system.(Including solenoid valves and manual valves, etc.); Connect the vacuum pump power supply, evacuate the system until the vacuum pressure gauge reads -0.1MPa, then rotate the suction cutoff valve stem counterclockwise to withdraw and tighten it after an appropriate period; maintain for 18-24 hours. If the vacuum level of the refrigeration equipment remains unchanged, the refrigeration system's vacuum test is considered passed.

2. Compressed Leak Detection

First, turn the refrigeration equipment exhaust cutoff valve rod clockwise to the bottom, causing the system to lose the circulation path at the compressor's exhaust outlet. Unscrew the fine-threaded plug of the multi-channel exhaust cutoff valve counterclockwise, allowing the exhaust outlet to communicate with the atmosphere. Open all valves within the system. Short-circuit the contacts of the low-pressure relay, temporarily removing the protective function. Start the compressor to expel the air inside the system into the atmosphere. Observe the vacuum gauge on the low-pressure end of the refrigeration equipment until the reading on the vacuum pressure gauge reaches-- Rotate and withdraw the exhaust cutoff valve rod after an appropriate time at 0.1 MPa. Maintain for 18-24 hours; if the vacuum level remains unchanged, it is considered合格.

Neither of the two refrigeration equipment testing methods should have an extended vacuuming time to prevent excessive wear and metal fatigue due to prolonged operation at high temperatures.