Abstract: A wafer style butterfly valve has a valve body including a through opening with a cylindrical wall coaxially surrounding an end portion of the fluid passage. The insert is retained within the valve body by at least one wire form held in an annular channel defined by facing annular grooves in the valve body wall and the insert peripheral wall. The wire form includes a member projecting therefrom for engaging a surface of the annular groove in the valve body wall or the annular groove in the insert peripheral wall. A tapered wall at one end of the insert provides for expansion of the wire form during insertion of the insert into the valve body.

Abstract: A wafer style butterfly valve has a valve body including a through opening with a cylindrical wall coaxially surrounding an end portion of the fluid passage. The insert is retained within the valve body by one or more resilient wire forms held in an annular channel defined by facing annular grooves in the valve body wall and the insert peripheral wall. The wire forms have circular sections while the insert groove has a semi-circular section, thereby providing a self-centering and self-locking effect. A tapered wall at one end of the insert provides expansion for the wire form during insertion of the insert into the valve body.