Pressure reduction piston type backflow preventer

Abstract

The invention relates to the technical field of pressure reduction backflow preventers, in particular to a pressure reduction piston type backflow preventer which comprises a pressure reduction piston type backflow preventer body which is provided with a first test ball valve through a first test water nozzle. A first-stage check valve is arranged on the left side of the interior of the pressure reduction piston type backflow preventer body and corresponds to the water inlet, and a second-stage check valve is arranged on the right side of the interior of the pressure reduction piston type backflow preventer body and corresponds to the water outlet. A spring is arranged between the first-stage check valve and the second-stage check valve and located on the outer wall of the valve rod sleeve and the outer wall of the valve rod, a pressure reducing valve is installed at the end, away from the pressure reducing piston type backflow preventer body, of the pressure reducing pipe, and the valve rod sleeve and the valve rod are adopted between the first-stage check valve and the second-stage check valve to be used in cooperation with the spring through a piston connecting structure. The accuracy of spring force design of the pressure reduction part can be improved, and the one-time assembly yield of products is improved.

Description

technical field [0001] The invention relates to the technical field of a decompression backflow preventer, in particular to a decompression piston type backflow preventer. Background technique [0002] The decompression backflow preventer (hereinafter referred to as the backflow preventer), as a valve component that can effectively prevent the dirty water in the branch circuit from flowing back to the main road, is widely used in developed countries such as Europe and the United States. In China, ordinary check valves are mainly used to prevent water backflow, and there are not many applications of backflow preventers, especially the applications of <DN50 are less. The decompression part of the currently used backflow preventer uses a diaphragm to transmit pressure and seal it. However, due to the complex processing technology of the diaphragm, the product quality is unstable, which affects the life of the backflow preventer. In addition, due to the reaction force of the ...

AI Technical Summary

Problems solved by technology

The decompression part of the currently used backflow preventer uses a diaphragm to transmit pressure and seal it. However, due to the complex processing technology of the diaphragm, the product quality is unstable, which affects the life of the backflow preventer. In addition, due to the reaction force of the diaphragm, the spring force design of the decompression part will be affected. The accuracy of the product has a certain impact, which affects the first-time assembly pass rate of the product. Therefore, a decompression piston-type backflow preventer is needed to improve the above problems.

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