弯曲半径小于或等于1.5倍管径的弯头,统称为小R弯头。采用小弯曲半径的弯头,可以使设备结构尺寸小,布置紧凑。随着四个现代化的迅速发展,小R变头在锅炉、石油化工、造船、原子能设备以及宇航工业中得到越来越广泛的应用。而且,弯头的弯曲半径越来越小。在生产实践中,虽然创造了很多,如中频弯管、带有轴向顶推力的冷弯,冷挤压弯管以及芯棒热推挤弯管等弯制 Bending radius less than or equal to 1.5 times the diameter of the elbow, collectively referred to as small R elbow. The use of small bending radius elbow, you can make the device structure of small size, compact layout. With the rapid development of four modernizations, the small R variable head has become more and more widely used in boilers, petrochemicals, shipbuilding, atomic energy equipment and the aerospace industry. Moreover, the elbow bending radius getting smaller and smaller. In the production practice, although a lot has been created, such as MF elbow, with axial thrust thrust cold bend, cold extrusion elbow and mandrel hot push elbows and other bending