Non-return valve for an exhaust duct of flue gasses

Abstract

The invention regards a non-return valve for a exhaust duct of flue gases of a boiler, comprising a valve body in which a passage opening of flue gases is defined, to said valve body a obturator being associated which, in a determined operating condition, closes said opening, said obturator comprising a first swing element, hinged on said valve body at said passage opening of flue gases. Advantageously, said obturator comprises a second swing element, hinged on said valve body at said passage opening of flue gases, said first and second swing elements being hinged at or in proximity to a middle plane of said opening.

1 . A non-return valve for a exhaust duct of flue gases of a boiler, comprising:
 a valve body in which a passage opening of flue gases is defined;   a obturator being associated with said valve body which, in a determined operating condition, closes said passage opening;   said obturator comprising a first swing element, hinged on said valve body at said passage opening of flue gases, and a second swing element, hinged on said valve body at said passage opening of flue gases;   said first and second swing elements being hinged at or in proximity to a middle plane of said opening.   
     
     
         2 . A valve according to  claim 1 , wherein said passage opening of flue gases comprises two structurally distinct passage zones of flue gases, each swing element being active on a respective zone of said passage zones of flue gases. 
     
     
         3 . A valve according to  claim 2 , wherein said two passage zones are substantially coplanar. 
     
     
         4 . A valve according to  claim 2 , wherein said two passage zones are of the same shape and size and they are symmetric with respect to said middle plane. 
     
     
         5 . A valve according to  claim 4 , wherein said two swing elements are of the same shape and size. 
     
     
         6 . A valve according to  claim 3 , wherein said plane to which said two passage zones substantially belong is inclined with respect to a longitudinal axis of said valve body. 
     
     
         7 . A valve according to  claim 1 , wherein said passage opening of flue gases is substantially defined in a plane which is inclined with respect to a longitudinal axis of said valve body. 
     
     
         8 . A valve according to  claim 7 , wherein said plane is inclined, with respect to said axis, of an angle comprised between 30° and 60°. 
     
     
         9 . A valve according to  claim 8 , wherein said plane is inclined of about 45° with respect to said axis. 
     
     
         10 . A valve according to  claim 1 , wherein said two swing elements are hinged to said valve body with clearance. 
     
     
         11 . A valve according to  claim 10 , further comprising said two passage zones being substantially coplanar, wherein said clearance is in a parallel plane with respect to, or coincident with, the one of said two zones. 
     
     
         12 . A valve according to  claim 1 , wherein said opening comprises at least one raised abutment edge for said two swing elements, said two swing elements being disposed to rest against said raised abutment when in said determined operating closing condition of said valve. 
     
     
         13 . A valve according to  claim 1 , wherein said valve body has a stop disposed to abut said swing elements, when said two swing elements are in an operating condition of maximum opening of said valve. 
     
     
         14 . A valve according to  claim 13 , further comprising said two passage zones being substantially coplanar and further comprising two hinges, one for each swing element, and wherein said two hinges are positioned side by side and said stop comprises a single element arranged astride said two hinges. 
     
     
         15 . A valve according to  claim 1 , wherein said valve body has substantially tubular shape. 
     
     
         16 . A valve according to  claim 15 , further comprising at least one circumferential gasket externally associated to said valve body and intended to provide seal with an internal wall of said duct. 
     
     
         17 . A valve according to  claim 15 , wherein said valve body externally has a plurality of centering elements, radially projecting from said valve body. 
     
     
         18 . A valve according to  claim 1 , wherein said valve body and said two swing elements are made of plastic material. 
     
     
         19 . A valve according to  claim 1 , wherein said valve body comprises at least one condensate drainage opening. 
     
     
         20 . A valve according to  claim 19 , further comprising said passage opening being inclined, wherein said at least one condensate drainage opening is arranged substantially below said passage opening of flue gases when the valve is mounted in such a manner that said longitudinal axis is arranged vertically. 
     
     
         21 . The valve assembly of  claim 19  further comprising at least one siphon connected to said at least one condensate drainage opening. 
     
     
         22 . The valve assembly of  claim 21 , wherein said at least one siphon has a smaller external size than said valve body. 
     
     
         23 . The valve assembly of  claim 21 , wherein said at least one siphon is at least partially housed in said valve body. 
     
     
         24 . The valve assembly of  claim 21 , wherein said at least one siphon is made of plastic material.