摘要 |
<p>An internal breathing system for a vacuum interface valve in a vacuum sewage system uses a vent port arranged in a partition between a remotely vented sump and a valve chamber for the vacuum interface valve located above the sump. A float valve normally opens the vent port to admit approximately atmospheric pressure air from the sump to the valve chamber, and the float valve closes the vent port if a mishap causes sewage to rise high enough to float the valve. Conduits preferably provide breathing communication for the vacuum interface valve and its controller from a region high in the valve chamber to avoid accidental transmission of sewage or condensate.</p> |