Abstract: In a rotary valve comprising a tubular housing (3) having, at the side part, a port (6) for communicating the inside and the outside thereof, and a tubular valve body (10) which is contained within the housing rotatably and has, at the side part, an orifice hole (11) capable of opposing to the port (6), the rotary valve of which the flow channel area formed by communicating the port (6) and the orifice hole (11) is changed by rotating the tubular valve body, at least one rotation stopping position with which the angle between the rotation stopping position at which the flow channel area is minimized and the rotation stopping position at which the flow channel area is maximized is equally divided, and the pressure loss differences between the adjacent rotation stopping positions are the same on condition that the passing flowing rate remains constant is provided.

Abstract: In a rotary valve comprising a tubular housing (3) having, at the side part, a port (6) for communicating the inside and the outside thereof, and a tubular valve body (10) which is contained within the housing rotatably and has, at the side part, an orifice hole (11) capable of opposing to the port (6), the rotary valve of which the flow channel area formed by communicating the port (6) and the orifice hole (11) is changed by rotating the tubular valve body, at least one rotation stopping position with which the angle between the rotation stopping position at which the flow channel area is minimized and the rotation stopping position at which the flow channel area is maximized is equally divided, and the pressure loss differences between the adjacent rotation stopping positions are the same on condition that the passing flowing rate remains constant is provided.