Backflow preventer

Abstract

The invention belongs to the field of check valves, and particularly discloses a backflow preventer. An inner cavity of a shell of the backflow preventer is divided into a first chamber and a second chamber; the induction cavity in the first cavity and the inlet valve clack form an induction cavity and are connected through an inlet reset piece. One side of the first chamber is connected with the water inlet, and the other side of the first chamber is connected with the second chamber through a connecting channel; the second cavity is connected with the water outlet and is communicated with the induction cavity through a backflow channel; the inlet valve clack is in sealing fit with the inlet valve seat at the water inlet, and the outlet valve clack is in sealing fit with the outlet valve seat at the connecting channel; when backflow occurs, the fluid enters the second cavity from the water outlet, closes the outlet valve clack and simultaneously flows into the induction cavity; the inlet valve clack is closed under the combined action of fluid pressure in the induction cavity and the inlet reset piece, and fluid backflow is prevented. Due to the introduction of the fluid in the induction cavity, the resistance characteristic of the inlet valve clack is changed, the water loss can be effectively reduced, and the reliability of the backflow preventer is improved.

Description

technical field [0001] The invention belongs to the technical field of check valves, and more specifically relates to a backflow preventer. Background technique [0002] The backflow preventer is used to prevent the backflow of water or a medium with physical and chemical properties similar to water, so as to protect the important parts of the pipeline system. Due to its high safety performance, small size and sensitive action, it has become the best choice for pipelines to prevent backflow pollution. Preferred product. [0003] The backflow preventer generally prevents fluid backflow by setting two check valves at the inlet end and the water outlet end. There are two kinds of backflow preventers in the prior art, one is the interlocking disc type backflow preventer, the two discs of this kind of backflow preventer are interlocking (the inlet disc and the outlet disc move together, and the same Open and close), the disadvantage of this kind of backflow preventer is that wh...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the above defects or improvement needs of the prior art, the present invention provides a backflow preventer to overcome the problem of low reliability of the linked disc type backflow preventer in the prior art, and the backflow prevention of the independent check v

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