| 摘要 |
A vacuum valve (15) includes: a pressure control chamber (83) for giving a vacuum force to a valve body (71) capable of connecting a valve operating chamber (25) with a vacuum passage; a detecting valve (68) capable of introducing a vacuum force into the pressure control chamber (83); a plunger (65) directly driven by a liquid detecting diaphragm (60), wherein the plunger (65) drives the detecting valve (68); and an opening time adjusting valve (74) which is opened so that the vacuum introduced into the pressure control chamber (83) can be released, wherein the opening time is automatically controlled by the vacuum in the vacuum discharge pipe (14). Furthermore, when the inside of a liquid level detecting pipe section (56) is quickly decompressed, pressure in a pressure adjusting chamber (102) is quickly released through a gap formed between a damping diaphragm (59) and supporting section (112). The pressure adjusting chamber (102) is communicated with an upper pressurizing chamber (81) through a communicating hole (103). Therefore, when the pressure adjusting chamber (102) is quickly decompressed, the upper pressurizing chamber (81) is also quickly decompressed. Due to the foregoing, resilient deformation of a liquid level detecting diaphragm (60) is quickly cancelled, and the pushing action conducted by a plunger (65) on a detecting valve (68) is released. <IMAGE> |
