METHOD OF MAKING TEES (VERSIONS) Russian patent published in 2013 - IPC B21C37/29 C21D8/10 

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming, particularly, to forming of tees and can be used in machine building for forging and welding-forging of pipeline tees. Proposed method comprises heating of rectangular billet to 750-1000°C, forming of cylindrical shell by billet bending and making lengthwise weld joint, and heating to 800-1000°C. Lengthwise billet pressing is performed, holes are bored in the billet for branch pipe and billet is heated to 800-1000°C. Biller radial pressing is performed to cool down larger part of said billet opposite the bored hole to temperature not over 550°C. Crosswise billet pressing is performed and branch pipe is flanged by male die its diameter not exceeding 1.5 diameter of said hole. Billet is heated to 800-1000°C and held at this temperature for at least 1 min per 1 mm of billet thickness. Thereafter, branch pipe is flanged by male die. Male die diameter equals branch pipe ID. In compliance with this version, the tee is made from tubular billet.

EFFECT: higher quality of tee for main pipe lines, lower metal input.

9 cl, 8 dwg, 2 ex