A valve assembly includes a valve housing having an upper body portion and a lower body portion that define an internal chamber for accommodating a valve member. The housing has axially aligned inlet and outlet ports. The valve assembly includes a generally spherical valve member seated within the internal chamber that defines first and second bores. The first bore defines a first longitudinal axis and the second bore defines a second longitudinal axis offset relative to the first longitudinal axis. The valve member is mounted for movement between a first position and a second position. The valve assembly includes a camming mechanism for moving the valve member between the first position and the second position, including cam surfaces formed on the exterior surface of the valve member and a cam pin formed on the interior surface of the upper body portion of the housing.