70年代以来,国内生产的LG-400、LHG-300等系列大功率等离子切割机,大都配用了两体组合式水冷切割炬。这种割炬的上、下两炬体组合处,有一个用聚四氟乙烯制作的中心绝缘垫,其形状见图1。该垫不仅要使上下炬体得到可靠的绝缘,而且还要保证冷却水的畅通无阻,以提高下炬体和喷咀的散热能力。但是由于中心垫与上下炬体的通水孔道位置难于对正,常有水堵塞现象,造成联接处漏水,使下炬体得不到良好的冷却。当漏水严重时,还会引起“双弧”,烧坏喷 Since the 1970s, the domestic production of LG-400, LHG-300 series of high-power plasma cutting machines, mostly equipped with a combination of two-body water-cooled cutting torch. This cutting torch, the torch combination of the next two, there is a center made of PTFE insulation pads, the shape shown in Figure 1. The pad not only ensures the upper and lower torch body to be reliably insulated, but also to ensure the smooth flow of cooling water to enhance the torch body and nozzle cooling capacity. However, due to the center pad and the upper and lower torch body through the water channel is difficult to align the location, often water clogging, resulting in joint leaks, the torch body can not get a good cooling. When serious water leakage, but also cause “double arc”, burning spray