Odour trap with check valve and air admittance valve

Abstract

A trap for a waste outlet for use in drainage facilities is described which provides a water seal. The trap comprises a one-way valve ( 23 ) at the trap inlet ( 14 ) and a pressure one-way valve ( 24 ) at the trap outlet ( 16 ) such that, in addition to prevent ingress of animals from the soil pipe to the buildings, prevents ingress of odours and the water seal being presence of a negative pressure differential across the outlet one-way pressure valve that air can pass through the pressure valve ( 24 ) to relieve the pressure differential but in the event of a positive pressure differential, air is prevented from passing through the oneway pressure valve ( 24 ).

1 - 34 . (canceled) 
     
     
         35 . A trap for a waste outlet, the trap comprising:
 a trap body defining an inlet and an outlet, the trap body further defining a convoluted flow path between the trap inlet and the trap outlet such that in use a water seal exists between the trap inlet and the trap outlet;   an inlet one-way flow valve located adjacent the trap inlet and adapted to permit flow or fluid from the trap inlet to the trap outlet but prevents flow from the trap outlet to the trap inlet; and   an outlet one-way pressure valve located adjacent the trap outlet;   wherein the trap outlet is displaced from the trap body by means of an outlet neck and wherein the outlet neck extends from the trap body and wherein the outlet one-way pressure valve is mounted to the outlet neck,   wherein, in use, in the presence of a negative pressure differential across the outlet one-way pressure valve, the outlet one-way pressure valve is operable to allow air to pass through the outlet one-way pressure valve to relieve the pressure differential but in the presence of a positive differential across the outlet one-way pressure valve, the outlet one-way pressure valve is operable to prevent air passing through the outlet one-way pressure valve.   
     
     
         36 . The trap according to  claim 35 , wherein the one-way pressure valve is in fluid communication with the outlet neck. 
     
     
         37 . The trap according to  claim 36 , wherein the one-way pressure valve is mounted to the outlet neck. 
     
     
         38 . The trap according to  claim 35 , wherein the outlet one-way pressure valve comprises a pressure valve inlet and a pressure valve outlet, wherein the pressure valve outlet is in communication with the trap body and wherein the pressure valve outlet is connected to the trap outlet's neck. 
     
     
         39 . The trap according to  claim 38 , wherein the pressure valve inlet comprises a pressure valve member. 
     
     
         40 . The trap according to  claim 39 , wherein the pressure valve member is positioned with respect to the pressure valve outlet such that the pressure valve member is located above the trap body outlet. 
     
     
         41 . The trap according to  claim 39 , wherein the pressure valve member is operable to move between a pressure valve open position and a pressure valve closed position and to move from a pressure valve closed position to a pressure valve open position in the presence of a threshold pressure. 
     
     
         42 . The trap according to  claim 41 , wherein the pressure valve member is operable to move between the pressure valve open position and the pressure valve closed position in the presence of a negative pressure differential across the pressure valve member. 
     
     
         43 . The trap according to  claim 39 , wherein, in use, the pressure valve inlet and the pressure valve outlet lie on different vertical planes, wherein the direction of flow through the pressure valve inlet and the direction of flow through the pressure valve outlet  36  are parallel but displaced apart. 
     
     
         44 . The trap according to  claim 43 , comprising a gravity driven pressure valve member. 
     
     
         45 . The trap according to  claim 39 , further comprising a void above the pressure valve member, wherein the void defines an air pocket, which provides a barrier between the pressure valve outlet and the pressure valve inlet. 
     
     
         46 . The trap according to  claim 35  wherein the inlet one-way flow valve comprises a diaphragm valve. 
     
     
         47 . The trap according to  claim 46 , wherein the diaphragm valve is a one-way duck bill valve.