Before refilling a chiller with refrigerant, the following steps are usually necessary to ensure the safety and efficiency of the system: 1, Inspect System Integrity: Ensure the chiller and associated components are not damaged or leaking. 2, Clean the System: Make sure the refrigerant circuit is clean, free of impurities, moisture, or other contaminants. 3, Check or Replace the Drier Filter: The drier filter is used to capture moisture and impurities. Before adding refrigerant, make sure it is either new or in good condition. 4, Evacuate the System: Use a vacuum pump to evacuate the system, ensuring there is no air or moisture inside. This also helps verify if the system is well-sealed. Typically, the system needs to be kept under high vacuum for a period to ensure complete removal of moisture and non-refrigerant gases. 5, Check System Oil: Ensure the oil in the compressor is appropriate and not contaminated. 6, Ensure the Correct Refrigerant is Used: Different chillers require different refrigerants. Make sure you're using the right refrigerant designed for the specific machine. 7, Refill According to Manufacturer's Guidelines: Use refrigerant filling equipment and operate according to the guidelines provided by the chiller manufacturer. 8, Monitor System Operation: After refilling, closely monitor the system's operation to ensure there are no leaks and that system pressures, temperatures, and other parameters are within normal ranges. 9, Check Protective Devices: Make sure all safety valves, pressure switches, and other protective devices are functioning correctly. 10, Ensure System Documentation is Updated: Document all work done, type of refrigerant used, and its quantity. When executing the above steps, always adhere to all applicable safety regulations and operational procedures, wear appropriate personal protective equipment, and consult experienced technicians wherever possible.