摘要 |
In a method for cold-working a piping component (10) with a pipe branch (16), particularly a valve housing of stainless steel, the pipe branch (16) is provided its length and final bore by forcing at least one ball or a drawing tool with partially spherical surface in direction from an inner cavity in the component and outwards. The inventive feature of the method is that before the drawing of an opening, there is performed clamping of the component (10) in a matrix tool composed of several parts (2, 4, 6, 8), the parts of the matrix tool fitting closely to the greater part of the external surfaces of the component, so that surfaces at the parts of the component to be coldworked are fixed during the drawing operation. Thereby, the drawing action will not distort the external or adjacent parts of the component or change the dimensions of the component, and control of the form and dimensions of the component is provided during the drawing action. Finishing treatment in the form machining is thus greatly reduced and material is saved by the method. |