UN3 series for copper and aluminum pipe welder for special plug-in resistance welding equipment, it can replace the original use of special high-pressure flash butt welding machine. The system uses a programmable logic controller (PLC) for the action logic control unit, a dedicated micro-welding controllers for welding process control unit, the use of high-quality and high-precision aluminum cylinder oil-bearing and precision machine tools with high precision light rod with guaranteed precision mechanical movement. Welding quality with a reliable, simple and intuitive control and adjustment, high production efficiency, basic seamless welding leakage phenomenon, producing high yield, etc., while overcoming the original welding technology needs within the welded pipe secondary processing and high voltage accident-prone disadvantages. Equipped with primary and secondary constant current constant voltage control system to ensure mass production, the quality of welding and welding results exactly. 1. Power supply voltage: 380-480VAC, 50 / 60Hz single-phase two. Rated Capacity: 50KVA-100KVA 3. Pipe diameter: Φ4-19.05mm brass: Φ4-19.05mm 4. Clamping cylinder stroke: 30mm 5. Lateral cylinder stroke: 100mm (adjustable)