A fluid control valve includes a housing body, a valve member, and a cap. The housing body includes a pipe part and a valve housing part. The valve housing part includes a valve opening, a pair of flat surfaces and an open end. In addition, the valve housing part houses the valve member configured to open and close the valve opening. The valve housing part has a central axis oriented perpendicular to a central axis of the pipe part. The cap closes the open end of the valve housing part. The flat surfaces are formed on opposite sides of a plane including the central axis of the valve housing part and the central axis of the pipe part. Each of the flat surfaces extend perpendicularly to the central axis of the valve housing.