Abstract: A fluid flow passage is available, between an inlet tube and an outlet tube, through a piston supported by a spring and equipped with an orifice connecting a pilot chamber and the outlet tube. A bellows chamber or a diaphragm chamber is provided with a pilot valve, which is directly connected with the bellows or the diaphragm, to open or close an orifice connecting the bellows chamber or the diaphragm chamber and a pilot chamber in which the piston is placed, in response to the pressure in the inlet tube monitored by the bellows or the diaphragm. The inlet tube and the outlet tube, together with the valve body, are formed by pressing or drawing at either end of a single tube which contains the valve means under the perfect airtight condition, to form a control valve to be employed for refrigerator and air conditioner.