Patent ID: 7591278
Filing Date: 2009-09-22
Classification: E03F,Y10T

Abstract:
1. Apparatus for controlling the flow of air into a sewer system and for controlling gaseous emissions from the sewer system, said apparatus comprising, in combination: a first fluid conduit comprising the upper leg of a vent pipe in communication with the ambient atmosphere and having a lower end; a second fluid conduit comprising the lower leg of said vent pipe leading to a sewer system and having an upper end, the lower end of the first fluid conduit and the upper end of the second fluid conduit respectively comprising first and second portions of a housing; a container comprising a water box attached to said housing and defining a container interior at least partially surrounding said housing for accommodating water, said first and second fluid conduits being operatively connected to said container and respectively in fluid-flow communication with said container interior through spaced first and second openings in said housing, said first opening being at a lower elevation than said second opening to form a water seal employing water in said container interior resisting air and gaseous emissions flow between said first opening and said second opening, said vent pipe having an interior cross-section substantially smaller than the cross-section of said container interior to provide a hydraulic advantage to the apparatus whereby any water in the vent pipe pushed a distance down in the vent pipe by atmospheric pressure due to a low pressure event in the sewer system will cause the level of water in the container interior to rise a fraction of said distance and whereby the water in the container interior when pushed downwardly by a high pressure event in the sewer system will escape into the vent pipe and rise at a higher rate in the vent pipe than the rate of lowering of water in the container interior caused by said high pressure event, resulting in a greater pressure differential being required to allow air to escape from said container interior than to draw air into said container interior from said vent pipe.