Back -fire relief flue check valve

The utility model provides a back -fire relief flue check valve, including check valve body, extension pipe, back -fire relief valve, thread tightening mouth, fixed knot, non return valve, shell, back-fire relief inflation lasso, interval gap, UPVC pipe, back -fire relief expansion block and mixed fire blocks, the utility model discloses the check valve can one -wayly prevent the oil smoke against the current during normal use, when kitchen or flue production conflagration, the contact of kitchen and flue can be blocked rapidly to the back -fire relief valve, accomplishes that fastest speed'sthe intensity of a fire that prevents stretchs to set up double -deck the packing in the back -fire relief valve, guarantee better back -fire relief effect, lower manufacturing cost. 本实用新型提供种阻火烟道止回阀，包括止回阀本体、加长管、阻火阀、螺纹固定口、固定扣、止回阀门、外壳、阻火膨胀套圈、间隔缝隙、UPVC管、阻火膨胀块和混合防火块，本实用新型止回阀，正常使用时可以单向防止油烟逆流，当厨房或烟道产生火灾时，阻火阀可以迅速阻断厨房和烟道的联系，做到最快速度的防止火势蔓延，并且阻火阀内设置双层填充，保证更好的阻火效果，更低的制造成本。