Screw-thread backflow prevention device being free from being equipped with external conduit

Abstract

The invention provides a screw-thread backflow prevention device being free from being equipped with an external conduit, which comprises an inlet water non-return water escape valve, an outlet water check valve and a connection port, wherein the inlet water non-return water escape valve, the outlet water check valve and the connection port are communicated with each other; a diaphragm is arranged inside a control chamber of the water escape valve, the diaphragm is flatly paved on the top end surface of a press plate to be covered by a lower cover and to be tightened onto a valve body of the water escape valve through bolt so as to form a control cavity, and water of a water inlet of the inlet water no-return valve flows through a through hole on the valve body and also flows through a through hole on the valve body of the water escape valve to enter the control cavity. The screw-thread backflow prevention device as the advantages that the backflow prevention device of the above structure is of a combination device which strictly limits that the pressure medium inside the pipeline flows in a single direction, the structure is compact, and the installation space can be saved; and the backflow medium inside the pipeline or the medium staying at the critical backflow state can be guided outside the pipe under any working conditions, and the air separation can be formed without any external accessory, so the device is free from the malicious damage, can ensure the safety of the water supply and can prevent the pollution.

Description

technical field [0001] The invention relates to a valve structure, in particular to a screw type backflow preventer. Background technique [0002] The current backflow preventer check valve adopts a "Y" type direct-flow structure, which is relatively long. Many renovation projects cannot be carried out as scheduled due to size problems. The drain valve adopts a "column"-shaped cavity structure or a "gourd"-shaped cavity structure. The control room adopts a single-diaphragm structure, and all control bypass pipes use external piping. On the one hand, the head loss of this structure is generally 7-9 meters. Because there are important structural design problems that have not been broken through, the head loss cannot be reduced. If this structure is used under the existing water supply conditions, the head loss will be large. Too many users cannot drink tap water, which is an important reason why this type of product cannot be promoted. On the other hand, when the diaphragm is...

AI Technical Summary

Problems solved by technology

[0002] The current backflow preventer check valve adopts a "Y" type direct-flow structure, which is relatively long. Many renovation projects cannot be carried out as scheduled due to size problems. The drain valve adopts a "column"-shaped cavity structure or a "gourd"-shaped cavity structure. The control room adopts a single-diaphragm structure, and all control bypass pipes use external piping

On the one hand, the head loss of this structure is generally 7-9 meters. Because there are important structural design problems that have not been broken through, the head loss cannot be reduced. If this structure is used under the existing water supply conditions, the head loss will be large. Too many users cannot drink tap water, which is an important reason why this type of product cannot be promoted. On the other hand, when the diaphragm is damaged, it is difficult to determine whether the backflow water enters the upstream through the bypass pipe, which is not conducive to the safety of water supply. The through pipe is a weak point, easy to be lost, destroyed, or poisoned by bad people. It is a fatal problem that this type of product has not solved so far. Governments of various countries are well aware of the importance of this type of product, but because of the fatal weakness of this type of product However, the water safety of residents cannot be guaranteed, and the water supply of the entire town brings major safety hazards.

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