Horng Shin produces and supplies solid state high frequency welders from 100kw to 800kw and suitable for pipes with thickness ranging from 0.2mm to 16mm. The product feature of solid state high frequency welder contains five main parts as follows: (1) Low voltage transformer (2) D. C power supply section (3) High frequency oscillator device (4) Water cooled system (5) Operating and control device In general, there are four advantages by using solid state high frequency welder as below: (1) Protected devices (2) Low internal voltages (3) Small compact size (4) Reduced purchasing of spare parts