METHOD FOR MAKING HOLLOW ARTICLES WITH BRANCH PIPES HAVING THE SAME STRENGTH AS MAIN TUBE Russian patent published in 2003 - IPC

FIELD: plastic metal working, possibly manufacture of hollow parts with branch pipes such as T-pieces and cross pieces used for mounting high-pressure pipelines. SUBSTANCE: method of forming hollow parts with branch pipes in detachable die having lengthwise and lateral ducts comprises steps of plastically deforming tubular blank by pressure of filler acting upon inner surface of blank and simultaneously upsetting end of blank; using detachable die having spheric cavity in center of crossing its ducts. Diameter of said cavity is equal to length of diagonal of rectangle whose length is equal to outer diameter of blank. Width of rectangle is equal to outer diameter of formed branch pipe. EFFECT: enhanced quality of articles. 6 dwg