A kind of Shui nationality air side Pu check (non-return) valve improvement,System when air side Pu stop to aquarium end supply when,Second valve block of the first valve block of the first valve body and the second valve body not by reply acts naturally caused by air thrust,The first valve opening and the second valve opening is presented simultaneously in off position as air stops input,At this point,If aquarium end has aqueous to flow backward the situation into air delivery outlet along appendix,By first,Two valve bodies first,Two valve blocks form two sections of Double reversing-proof effectiveness for preventing it from passing through to the aqueous of entrance,Effectively ensure safety when the low gesture in air side Pu is installed and used.一種水族空氣幫浦止逆閥改良，係當空氣幫浦停止對水族箱端供氣時，第一閥體的第一閥片及第二閥體的第二閥片未受空氣推力所產生的自然回復動作，則使第一閥孔及第二閥孔隨著空氣停止輸入而同時呈現在關閉狀態，此時，水族箱端若有水液沿著輸氣管倒灌入空氣輸出孔的情形，藉由第一、二閥體的第一、二閥片對進入的水液形成二段阻止其通過的雙重止逆效用，有效確保空氣幫浦低勢安裝使用時的安全性。
