we supply dn50, dn75, dn110 and dn160 air admittance valves and customize other specifications as per samples.

features:
1) the fine weather-proof surface sealing ring keeps tight and rubber flap has an opening/closing sensitivity=14mm water column.
2) it works under gravity difference and merely allows gas-suction without discharge so as to keep odor within pipeline. it fast replenishes negative pressure within pipeline to protect the water seal of other drainage utensils from damage.
3) it is suitable for multi-story and high-rising buildings due to large gas suction capacity and equivalent drainage capacity.
4) it substitutes single-row drainage system for dual-row gas-discharge and drainage system and roof venting caps, reducing cost of roof drainage works and protects roof from leakage.
5) it keeps silent in operation and has service life as that of drainage pipeline. it has good flame-proof performances and in advance alarming of blocking of pipeline.
6) when the downstream drainage pipeline is blocked, the upstream air is enclosed in pipeline to prevent drainage of upstream.
7) if the drainage level lowers slowly, it denotes blocking of drainage pipeline and need in advance un-blocking.
8) when negative pressure builds up, the valve disk floats up along its centering rail, lets in the air and prevents the water seals from being sucked by negative pressure.
9) when there is no negative pressure, the valve disk drops by its weight along the centering rail to close the valve mouth, and prevent the odor gases from coming via the drainage system.