Pipeline fluid non-return device and method

The invention relates to a pipeline fluid non-return device and method.The non-return device comprises a shell, the shell is internally provided with a first cavity, a second cavity and a third cavity for fluid to pass through, the first cavity communicates with the second cavity through a first through opening, and the first through opening is provided with a first non-return valve; the second chamber is communicated with the third chamber through a second port, and the second port is provided with a second check valve; a safety valve is further arranged between the first check valve and the second check valve, and backflow fluid can be discharged out of the system in time when backflow occurs. By arranging the two check valves of mechanical structures, the whole water supply system can be prevented from being polluted, the working reliability is high, and the cost is low. 本申请涉及一种管道流体止回装置及方法，止回装置包括壳体，壳体内设有供流体通过的第一腔室、第二腔室和第三腔室，第一腔室与第二腔室通过第一通口连通，第一通口设有第一止回阀；第二腔室与第三腔室通过第二通口连通，第二通口设有第二止回阀；第一止回阀和第二止回阀之间还设有安全阀，能够在