在工业锅炉及冶金备件上，常常使用大直径环形管。目前，对这类环形管的制作一般是采用中频弯管机加热弯制，效果很好。但中频弯管机不适宜弯制无磁性金属管，且耗能大，又受加工量影响，一般中小企业并无这种设备。多年来，我厂在制作这类环形管时，采用简易模具，冷态下压弯 On industrial boilers and metallurgical spare parts, large diameter annular pipes are often used. At present, the production of such a toroidal tube is generally used IF bending machine heating bending, the effect is very good. However, IF bending machine is not suitable for bending non-magnetic metal pipe, and energy consumption, but also affected by the amount of processing, SMEs generally do not have such equipment. Over the years, I plant in the production of such ring tube, the use of simple mold, cold bend under pressure