US Patent 7004452 Valve seal assemblies and methods

A method of sealing a valve engaging member to a valve body about a borehole and structure thereof. Two seal members disposed on either side of the valve engaging member include a seat member adjacent the valve engaging member and a pocket insert adjacent the seat member. The pocket inserts fit within first and second pockets of the valve body. A C-shaped seal ring is disposed between the seat member and pocket insert, and two U-shaped seal rings are disposed between the pocket insert and the valve body. One of the U-shaped seal rings between the pocket insert and the valve body functions both as a radial seal ring and a retaining ring.