A forging process for a conical valve shell forging of a large ball valve device

Abstract

This invention relates to a forging process for a conical valve shell forging used in large ball valve equipment. The process for producing valve shell forgings includes the following steps: chamfering and removing risers from a steel ingot; preparing a forging ratio, shaping the billet into a drum shape, and then punching a hole; a second forging to enlarge the hole; then punching down from one end with a large punch to pre-form a billet with one end having a larger outer diameter and inner hole, and the other end having a smaller outer diameter and inner hole, pre-forming the billet into a conical shape; a third and fourth forging, after the billet is pre-formed into a conical shape, it is fitted onto a mandrel, which is positioned between a first and second mandrel. An adjustment device is installed below the larger diameter end of the conical pre-formed material, adjusting and enlarging the hole to the desired angle, forging the inner wall of the conical pre-formed material into an arc surface, and finally forging the final shape. This invention reduces the forging allowance of the inner hole, thereby reducing the weight of the forging and saving raw materials.

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