Pressure release type backflow preventer

Abstract

The invention relates to a pressure release type backflow preventer which comprises a water inlet ball valve, a first-stage check valve, a second-stage check valve and a water outlet ball valve, wherein a bypass draining pressure reducing valve is installed between the first-stage check valve and the second-stage check valve and comprises a valve cover and a valve body. The backflow preventer is characterized in that a piston body which can move left and right is distributed inside an inner cavity of the draining pressure reducing valve and divides the inner cavity into a left cavity and a right cavity, wherein the left cavity is communicated with a master water inlet by a channel arranged on the valve cover of the draining pressure reducing valve, and the right cavity leads a water inletto be communicated with a water outlet of the draining pressure reducing valve by a ring-shaped seat; the circumferential surface of the piston body is distributed with a ring-shaped sealing ring which is used for realizing sliding seal with the wall surface of the inner cavity, and the right side of the piston body is provided with a gasket which is matched and sealed with the ring-shaped seat; and a spring is supported between the piston body and the ring-shaped seat. Therefore, the pressure release type backflow preventer has simple and reasonable structure, and is easy to produce and assemble.

Description

technical field [0001] The invention relates to an anti-backflow valve device. Background technique [0002] In all kinds of water supply pipelines, the various check valves currently used cannot effectively prevent the pressure water from flowing back from the branch pipe to the main pipe and causing backflow pollution, especially in the water supply network of drinking water. serious health hazards. In the production process, it becomes a hidden danger of unsafe liquid supply. [0003] For this reason, some scientific and technical personnel have developed a pressure relief type backflow preventer, which consists of a water inlet ball valve, a water outlet ball valve, a primary check valve, a secondary check valve and a water relief valve bypassed by it. The pressure reducing valve is installed between the primary check valve and the secondary check valve. For the specific structure, see figure 1 , The spool that can move left and right is arranged in the inner cavity o...

AI Technical Summary

Problems solved by technology

[0002] In all kinds of water supply pipelines, the various check valves currently used cannot effectively prevent backflow pollution from backflow of pressure water from the branch pipe to the main pipe, especially in the water supply network of domestic drinking water. serious harm to the health of

Become a hidden danger of unsafe liquid supply in the production process

[0003] For this reason, some scientific and technical personnel have developed a pressure relief type backflow preventer, which consists of a water inlet ball valve, a water outlet ball valve, a primary check valve, a secondary check valve, and a water relief pressure reducing valve bypassing it. The pressure reducing valve is installed between the first-stage check valve and the second-stage check valve. For the specific structure, see figure 1 The spool that can move left and right is arranged in the inner cavity of the drain pressure reducing valve. The spool is connected by a small piston and a large piston with bolts, and both the small piston and the large piston are equipped with a diaphragm pad to divide the inner cavity into left and right. The disadvantage of the chamber is that the valve core structure is not simple enough, and the diaphragm processing is difficult, the technology is difficult to master, and there is a reaction force, so the design needs to be further improved

Images