PROCESS OF FIXING PIPES IN PIPE GRATES Russian patent published in 2001 - IPC

FIELD: plastic metal working. SUBSTANCE: in particular, invention refers to fixing pipes with bimetal profiled ends in pipe grates of heat exchange equipment. Annular groove is made in advance in internal surface of each end of pipe. Bushing of cladding material is put into annular groove. External ring boss is formed on external surface of end of pipe simultaneously with plastic deformation of material of pipe over butts of bushing. Then pipe is installed into pipe hole of pipe grate made with ring grooves. In this case external ring boss of pipe is aligned with proper ring groove of pipe hole. Pipe is fixed against possible movement and in pipe hole by compression force applied to internal surface of pipe. Internal ring protrusion of pipe is formed in process of fixing. Fixing is conducted with formation of boundary layer between materials of pipe and cladding bushing. Bushing is installed in annular groove of pipe by means of pressing in, by reduction of end of pipe crimped in advance or by reduction with simultaneous crimping of end of pipe. Joint reduction of end of pipe and bushing can be used after installation of bushing into annular groove of end of pipe. EFFECT: raised strength, tightness and corrosion resistance of obtained connections. 4 cl, 7 dwg