Abstract: A poppet type change-over valve assembly suitable for switching a fluid flow direction and capable of dealing with a large fluid flow with a small valve displacement and small valve operating force. The valve assembly characteristically comprises an annular float valve which is loosely mounted around a main valve body and has parallel or concentric outer and inner sealing edges for engagement with conical valve seats which are formed on the main valve body and an inner wall surface of the valve casing. The annular float valve is adapted to be tightly held between the conical valve seats of the main valve body and the valve casing by cooperation of the main valve body and a fluid pressure prevailing in the valve chamber when the valve is switched to a desired change-over position thereby establishing a tight seal around the main valve body for connecting a fluid inlet port with a selected fluid output port of the valve.