Aluminum Alloy Corona Hollow rings mainly use for HV overhead transmission line，HV Surge Arresters，High Voltage Test Equipment，such as HV composite silicone rubber long rod insulators Corona Rings/Grading rings. High Voltage Capacitor Banks Corona Rings/Grading rings GIS (Gas Insulated Switchgear) Corona Rings/Grading rings Transmission line & Substation Corona Rings/Grading rings TRIDELTA HV Surge Arrestor Corona Rings/Grading rings Shunt Reactor Corona Rings/Grading rings Power Transformer, current transformer, AC test transformer, voltage transformer Power cable (accessory), High voltage laboratory (High voltage test equipment), Impulse voltage test system, HV capacitor bank, HV transmission line (overhead line) Transformer aluminum alloy rings and so on Corona Ring Installation for Transmission Insulators High Voltage Insulator with Corona rings