Abstract: A valve for controlling fluid flow while permitting flow in only one direction includes a housing having a spherical central opening and connections to permit attachment to fluid flow lines at opposite ends of the housing. The spherical opening is configured to permit fluid flow through the housing. A spherical member is adapted to fit within the spherical central opening of the housing. The spherical member has an opening bored through its center and may be aligned with the housing connections to allow fluid communication between them and positioned perpendicular to the housing connections to prevent fluid communication between them. A rotation member is provided to operate in conjunction with the spherical member to rotate the spherical member within the housing. A closing member is mounted within the spherical member, and is sized to close off the opening bored through the center of the spherical member for one direction of fluid flow.