MEMBRANE VALVE WITH MEDIUM OR LARGE CALIBER CONTROLLED BY LOW MOMENT

摘要

A membrane valve with a medium or large caliber controlled by a low moment has a valve body (1) and a valve cover (2). The valve body (1) is internally provided with a valve passage (11), a valve seat (12) and a valve core. A connecting cavity (13) is provided between the valve cover (2) and the valve body (1) to communicate a medium inlet passage (111) and a medium outlet passage (112). The valve core is composed of a membrane (14) and an erecting assembly (15) thereof. The membrane (14) and the erecting assembly (15) thereof are positioned between the medium inlet passage (111) and the connecting cavity (13) as well as between the medium outlet passage (112) and the connecting cavity (13) and are in contact with the valve seat (12). The end surface of the part of the membrane (14) that faces the medium inlet passage (111) is provided with several pilot holes (113). A communication passage (16) which is in communication with the connecting cavity (13) is provided on the valve body (1), a pressure relief passage (17) that is in communication with environment is provided in the communication passage (16), and a micro-switch (18) is provided between the pressure relief passage (17) and the communication passage (16). The membrane valve can control the opening and closing of a valve with a medium or large caliber and the flux adjusting thereof by a low moment.