Patent ID: 9022353
Filing Date: 2015-05-05
Classification: F16K

Abstract:
1. A ball valve that comprises a valve body having a flow inlet passage, a flow outlet passage, and a communication portion formed between the passages, a ball having a flow communication passage and installed rotatably around a reference axis in the communication portion of the valve body, and a ball seat having an approximately cylindrical shape with a desired opening formed on a circumferential wall and placed between the ball and the valve body, wherein the flow inlet passage and the flow outlet passage are opened and closed by rotating the ball around a reference axis, the ball seat and the valve body are made of different materials, a cylindrical shaped protrusion, a leading edge of which forms a circle, is formed on the harder component between a bottom of the ball seat and a ball seat support surface of the valve body to bite into the softer component, and the protrusion is cut off in at least one place on the leading edge and a surface of the softer component facing the protrusion is a flat surface, wherein in an upper portion of the ball seat presser, a packing is maintained, the packing is pressed downward by a packing presser screw screwed to inner circumference of a cylindrical portion of the valve body through a packing presser, and tightening force of the packing presser screw is adjusted, so that the ball seat is maintained between the ball seat presser and the ball seat support surface.