Low-resistance self-discharge backflow preventer

Abstract

The invention relates to the technical field of valves, in particular to a low-resistance self-discharge backflow preventer, solving the problems of instable work, poor safety performance, large energy loss and complicated structure of the traditional backflow preventer. The low-resistance self-discharge backflow preventer comprises a valve body and a valve cap arranged at one end of a water inlet of the valve body and is characterized in that a water discharge opening is arranged at the middle of the valve body; a sleeve is arranged at the core part of the valve body at the water discharge opening; a circular blade and a spring seat are arranged at one end of the valve body towards the water inlet of the valve body; a third spring is arranged between the outside diameter of the sleeve and the inside diameter of the valve body; a first one-way valve is arranged at the core part of the valve cap; one end of the first one-way valve is matched with the sleeve; a second one-way valve is arranged at one end of the sleeve towards a water outlet of the valve body; and the second one-way valve comprises a four-claw sliding valve and the matching part of the sliding valve and the sleeve is the width of four claws. The invention has the advantages of high partition safety, small loss for a tap when a medium passes through the preventer and effective prevention on the pollution caused by the backflow.

Description

technical field [0001] The invention relates to the technical field of valves, in particular to a low-resistance self-draining backflow preventer for preventing pipeline liquid from backflowing. Background technique [0002] The backflow preventer, also known as the sewage flow cut-off valve, is a method to prevent sewage from polluting the water quality of the water supply source when the domestic drinking water pipeline backflows, and is also suitable for pipelines where the medium is not allowed to flow backward physically and chemically. There are mainly two types of existing backflow preventers. One is composed of two check valves connected in series, which has simple structure, small flow resistance and low price. The non-return function has poor safety and is only used in occasions that do not require high isolation; the other is composed of two separated non-return valves and an intermediate discharge chamber with decompression, which has excellent performance and re...

AI Technical Summary

Problems solved by technology

[0003] The purpose of this invention is to solve the problems of unstable operation, poor safety performance, large energy loss and complicated structure of the existing backflow preventer, and to provide a low-resistance self-draining backflow preventer. The water inlet and outlet of the body are respectively equipped with one-way valves, and the combination of the sleeve and the one-way valve is set in the middle of the valve body for backflow and drainage, which has high safety, small flow resistance, and head loss when the medium passes through. Only 2-3 meters of water column (flow rate 3m / s)

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