Dual Air Admittance Valve with Locking Mechanism and Pressure Indicator

Abstract

An apparatus to allow or stop an air flow into an enclosed environment or piping system comprises (a) a housing, (b) a first valve seat, (c) a first sealing member, (d) a second valve seat, (e) a second sealing member, (f) at least one locking mechanism configured to limit a movement of the first sealing member and/or the second sealing member; wherein the first sealing member moves away from the first valve seat when the second pressure is greater than the first pressure in a predetermined pressure difference; wherein the second sealing member moves away from the first valve seat when the third pressure is greater than the second pressure in a predetermined pressure difference; wherein the first pressure communicates with a system pressure in the piping system; and wherein the third pressure communicates with an ambient air pressure.

What is claimed is: 
     
         1 . An air admittance valve apparatus to allow or stop air into system said air admittance valve apparatus comprising:
 (a) a housing having an upper flow passage, a middle flow passage, a lower flow passage, said lower flow passage for communicating with the ambient environment, said upper flow passage for connection to and communication with said system, said middle flow passage between said lower flow passage and said upper flow passage;   (b) a first valve seat disposed within said upper flow passage, an at least one opening formed on said first valve seat, said at least one opening being in communication with said middle flow passage;   (c) a first sealing member disposed in said upper flow passage, said first sealing member is configured for movement in said upper flow passage with respect to said first valve seat, said first sealing member is configured for sealing said first valve seat;   (d) a second valve seat disposed within said middle flow passage, an at least one opening formed on said second valve seat, said at least one opening being in communication with said lower flow passage;   (e) a second sealing member disposed in said middle flow passage, said second sealing member is configured for movement in said middle flow passage with respect to said second valve seat, said second sealing member is configured for sealing said second valve seat;   
     
     
         2 . The apparatus of  claim 1 , wherein said upper flow passage is above said middle flow passage, said middle flow passage is above said lower flow passage. 
     
     
         3 . The apparatus of  claim 1 , wherein an opening is formed on said housing, said opening being in communication with said middle flow passage. 
     
     
         4 . The apparatus of  claim 3 , further comprising a pressure indicator disposed within said opening formed on said housing. 
     
     
         5 . The apparatus of  claim 4 , wherein said pressure indicator is responsive to said middle flow passage pressure and said ambient environment pressure differences. 
     
     
         6 . The apparatus of  claim 4 , wherein said pressure indicator is a pliable diaphragm. 
     
     
         7 . The apparatus of  claim 1 , wherein a first pressure exists in said upper flow passage, a second pressure exists in said middle flow passage, a third pressure exists in said lower flow passage. 
     
     
         8 . The apparatus of  claim 7 , wherein said first sealing member moves away from said first valve seat when said second pressure is greater than said first pressure in a pressure difference. 
     
     
         9 . The apparatus of  claim 7 , wherein said second sealing member moves away from said second valve seat when said third pressure is greater than said second pressure in a pressure difference. 
     
     
         10 . The apparatus of  claim 7 , wherein said first sealing member moves away from said first valve seat when said second pressure is greater than said first pressure in a predetermined pressure difference;
 wherein said second sealing member moves away from said second valve seat when said third pressure is greater than said second pressure in a predetermined pressure difference;   wherein said first pressure communicates with a system pressure in said system; and wherein said third pressure communicates with an ambient air pressure.   
     
     
         11 . An air admittance valve apparatus to allow or stop air into an enclosed environment or piping system said air admittance valve apparatus comprising:
 (a) a housing having an upper flow passage, a middle flow passage, a lower flow passage, said lower flow passage for communicating with the ambient environment, said upper flow passage for connection to and communication with said system, said middle flow passage between said lower flow passage and said upper flow passage;   (b) a first valve seat disposed within said upper flow passage, an at least one opening formed on said first valve seat, said at least one opening having an inner diameter being in communication with said middle flow passage;   (c) a first sealing member disposed in said upper flow passage, said first sealing member is configured for movement in said upper flow passage with respect to said first valve seat, said first sealing member is configured for sealing said first valve seat;   (d) a second valve seat disposed within said middle flow passage, an at least one opening formed on said second valve seat, said at least one opening being in communication with said lower flow passage;   (e) a second sealing member disposed in said middle flow passage, said second sealing member is configured for movement in said middle flow passage with respect to said second valve seat, said second sealing member is configured for sealing said second valve seat;   (f) a at least one locking mechanism   
     
     
         12 . The apparatus of  claim 11 , wherein said first sealing member is configured and dimensioned to rest on said first valve seat substantially blocking said at least one opening of said first valve seat. 
     
     
         13 . The apparatus of  claim 11 , wherein said second sealing member is configured and dimensioned to rest on said second valve seat substantially blocking said at least one opening of said second valve seat. 
     
     
         14 . The apparatus of  claim 11 , wherein said first sealing member can move in said upper flow passage above said first valve seat. 
     
     
         15 . The apparatus of  claim 11 , wherein said second sealing member can move in said middle flow passage above said second valve seat. 
     
     
         16 . An apparatus to allow or stop an air flow into an enclosed environment or piping system comprising:
 (g) a housing having an upper flow passage, a middle flow passage, a lower flow passage, said lower flow passage for communicating with the ambient environment, said upper flow passage for connection to and communication with said system, said middle flow passage between said lower flow passage and said upper flow passage;   (h) a first valve seat disposed between said upper flow passage and said middle flow passage, an at least one opening formed on said first valve seat, said at least one opening having a tapered part;   (i) a first sealing member disposed in said upper flow passage, said first sealing member is configured for movement in said upper flow passage with respect to said first valve seat, said first sealing member is configured for sealing said first valve seat;   (j) a second valve seat disposed between said middle flow passage and said lower flow passage, an at least one opening formed on said second valve seat, said at least one opening said at least one opening having a tapered part;   (k) a second sealing member disposed in said middle flow passage, said second sealing member is configured for movement in said middle flow passage with respect to said second valve seat, said second sealing member is configured for sealing said second valve seat;   (l) a at least one locking mechanism   
     
     
         17 . The apparatus of  claim 16 , wherein said first sealing member is configured and dimensioned to rest on said first valve seat substantially blocking said at least one opening of said first valve seat. 
     
     
         18 . The apparatus of  claim 16 , wherein said second sealing member is configured and dimensioned to rest on said second valve seat substantially blocking said at least one opening of said second valve seat. 
     
     
         19 . The apparatus of  claim 16 , wherein said first sealing member can move in said upper flow passage above said first valve seat. 
     
     
         20 . The apparatus of  claim 16 , wherein said second sealing member can move in said middle flow passage above said second valve seat.