Decentering forma metal sheet butterfly valve

摘要

PROBLEM TO BE SOLVED: To simplify a structure and reduce a manufacturing cost by arranging a ring to back up the elasticity of a metal seat ring between the metal seat ring and a valve body, and forming a clearance allowing inflow of pressure fluid between this back up ring and a seat ring retainer. ;SOLUTION: A back up ring 6 is arranged on the back part of a metal seat ring 4 fixed on a valve body 1 by a seat ring retainer 5, thereby the elasticity of the metal seat ring 4 is backed up. A first clearance 8 allowing the elastic deformation of the metal seat ring 4 is formed between the metal seat ring 4 and the valve body 1, thereby the tightly sticking property of the metal seat ring 4 to a valve element 2 can be enhanced. A second clearance 9 is formed between the back up ring 6 and the seat ring retainer 5, and the metal seat ring 4 is elastically deformed together with the back up ring 6 by fluid pressure led to flow from the second clearance 9 into the back part space 10 of the back up ring 6, thereby the tightly sticking property of the metal seat ring 4 to the valve element 2 can be enhanced.;COPYRIGHT: (C)1999,JPO