Patent ID: 9657468
Date: 2017-05-23
CPC Classifications: E03C,E03F,F16K

Claim:
1. An apparatus to allow or stop an air flow into an enclosed environment or piping system, comprising: (a) a housing having an upper flow passage, a middle flow passage, a lower flow passage, wherein said upper flow passage is above said middle flow passage, wherein said middle flow passage is above said lower flow passage, wherein an upper flow passage pressure exists in said upper flow passage, wherein a middle flow passage pressure exists in said middle flow passage, and wherein a lower flow passage pressure exists in said lower flow passage; (b) a first valve seat, wherein said first valve seat is between said upper flow passage and said middle flow passage, and wherein a first opening is formed on said first valve seat; (c) a first valve diaphragm, wherein said first valve diaphragm is dimensioned and configured to be inside said upper flow passage, wherein said first valve diaphragm is configured and dimensioned to substantially cover said first opening of said first valve seat, wherein said first valve diaphragm has an outer circumference, wherein said first valve diaphragm further comprises a plurality of protruding members extending radially from said outer circumference, wherein said first valve diaphragm has a predetermined weight, wherein said first valve diaphragm can move upwardly and downwardly above said first valve seat, wherein said first valve diaphragm is moved upwardly above said first valve seat when said middle flow passage pressure is greater than the upper flow passage pressure and said predetermined weight of said first valve diaphragm, and wherein said first valve diaphragm covers said first opening when said middle flow passage pressure is less than or equal to the upper flow passage pressure and said predetermined weight of said first valve diaphragm; (d) a second valve seat, wherein said second valve seat is between said middle flow passage and said lower flow passage, and wherein a second opening is formed on said second valve seat; and (e) a second valve diaphragm, wherein said second valve diaphragm is dimensioned and configured to be inside said middle flow passage, wherein said second valve diaphragm is configured and dimensioned to substantially cover said second opening of said second valve seat, wherein said second valve diaphragm has an outer circumference, wherein said second valve diaphragm further comprises a plurality of protruding members extending radially from said outer circumference, wherein said second valve diaphragm has a predetermined weight, wherein said second valve diaphragm can move upwardly and downwardly above said second valve seat, wherein said first valve diaphragm is in an open position when said first valve diaphragm is moved away from said first valve seat, wherein said first valve diaphragm is biased towards a closed position by said predetermined weight of said first valve diaphragm so that said first valve diaphragm is disposed on said first valve seat, wherein said second valve diaphragm is in an open position when said second valve diaphragm is moved away from said second valve seat, wherein said second valve diaphragm is biased towards a closed position by said predetermined weight of said second valve diaphragm so that said second valve diaphragm is disposed on said second valve seat, wherein said second valve diaphragm is moved upwardly above said second valve seat when said lower flow passage pressure is greater than the middle flow passage pressure and said predetermined weight of said second valve diaphragm, and wherein said second valve diaphragm covers said second opening when said lower flow passage pressure is less than or equal to the middle flow passage pressure and said predetermined weight of said second valve diaphragm.