FLOW CONTROL VALVE AND MANUFACTURING METHOD THEREFOR

It is an object to provide a flow control valve in which corrosion is less likely to occur in the vicinity of a radial step portion in a gas passage of a housing and to provide a method for manufacturing the same. A flow control valve 1 includes: a housing 2 formed with a gas passage 20 including a first cylinder member accommodating portion 21, a second cylinder member accommodating portion 22, and a radial step portion 23; a first cylinder member 3 accommodated in the first cylinder member accommodating portion 21; a second cylinder member 4 accommodated in the second cylinder member accommodating portion 22; and a valve body 5 that is rotatably arranged inside the first cylinder member 3 and the second cylinder member 4 in the radial direction. The housing 2 is formed of cast iron. At least surfaces of the first cylinder member 3 and the second cylinder member 4 are formed of a highly corrosion resistant material. At least one of a first axial end surface 30 and a second axial end surface 40 includes an opposing portion 401 that opposes the radial step portion 23 in the axial direction. A gas seal structure 61 is arranged between the opposing portion 401 and the radial step portion 23.