When selecting a copper accumulator, you must prioritize material purity (typically C12200 Phosphorus-Deoxidized Copper) to ensure excellent weldability and corrosion resistance. Key technical parameters include the Maximum Working Pressure (MWP), which must align with the refrigerant used (e.g., R410A requires higher pressure ratings than R22), and the storage capacity, which should be sized to handle at least 50% of the total system refrigerant charge to prevent liquid slugging. Additionally, verify the U-tube design and orifice diameter to ensure proper oil return to the compressor.