| 摘要 |
The object of the present invention is to prevent opening of a vacuum-actuated valve if the available vacuum is far too low. Such valves are e.g. utilised for letting sewage fluid into a piping system in which the sewage fluid is transported by means of vacuum. Said object is met in that a diaphragm 13 senses the difference between the available vacuum and the atmospheric pressure, and in dependence of this difference actuates a body 17 which opens a passage 12, 21 between the piping system and said valve. The body 17 is loaded in opposite direction by means of a spring 23, and in its closed position also by a force arising from the difference between atmospheric pressure and the available vacuum. <IMAGE> |
