摘要 |
[Problem] To provide a normally closed three-port valve which is formed so as to have a structure that combines components that can be manufactured from molded articles with which a valve member can easily be molded and assembled, and for which manufacturing cost for the valve member is reduced. [Solution] A normally closed three-port valve equipped with a valve member (3), which is biased in the valve-closing direction from a supply port (P) side with respect to a main valve seat (2) within a valve body (1), and which is opened by a valve-opening rod (5) provided with a discharge flow path (6), with a back pressure chamber (8) behind this valve member communicating with a flow path on an output port (A) side by means of a ventilation hole (9), thereby balancing the fluid pressure acting on the front and rear surfaces of the valve member, wherein the valve member is formed by means of a valve member main body (31), a seat member (32), which is formed by a disc-shaped seal material having rubber elasticity, and is provided with a main seat surface (32a), an exhaust seat surface (32b), and a through-hole (32c) opened therebetween and forming the ventilation hole (9), a securing member (33) that secures the seat member to the valve member main body, and a pressing frame (34) at the circumference of the seat member, with the structural components of the valve member being formed by means of molded articles. |