METHOD OF THREADED JOINTS WELDING Russian patent published in 2009 - IPC B23K37/04 B23K31/02 B23P19/06 

FIELD: technological processes.

SUBSTANCE: mated parts are preliminarily tightened by torque spanner with torque fixation. Period of thread tightening is determined with optimal torque at minimum value of misalignment, which is assessed by values of radial divergence of mated parts. Afterwards final thread tightening is done until optimal torque value is obtained. Then intermediate fixation is done at the butt end of threaded joint by means of tack welding. In order to do this, section is defined, which corresponds to maximum radial divergence on controlled surface in relation to base surface of joint parts. The first tack weld is made on diametrically opposite section. Mutual position of mated parts is measured, and sections for another two tack welds are identified in the same manner, then tack welds are made, and welding is performed along joint perimeter.

EFFECT: high accuracy of mutual position of two mated parts without toughening of technology for manufacture of separate product parts.

3 dwg, 1 tbl