Low-resistance water-saving backflow preventer

Abstract

The invention discloses a low-resistance water-saving backflow preventer which comprises a casing, a water inlet valve and an elastic sealing device, wherein the water inlet valve and the elastic sealing device are positioned in the casing. The elastic sealing device partitions the inside of the casing into a main chamber and a control chamber, two sealing lines are arranged on the contact surface of the outer side of a valve seat of the water inlet valve and a valve plate, a plurality of channels are formed in the valve seat between the two sealing lines and communicated with the control chamber through through holes in the casing, and a check valve is arranged in each through hole in the casing and can restrain media to flow from the control chamber to the main chamber. The check valves are arranged in the through holes in the valve body, and the media is prevented from flowing to the main chamber from the control chamber through the check valves. When water is supplied normally, pressure drop of the control chamber caused by injection can be restrained effectively, and abnormal opening of a water escape valve is avoided effectively.

Description

technical field [0001] The invention relates to the technical field of valves, in particular to a low-resistance water-saving backflow preventer. Background technique [0002] Chinese patent 201310631017.2 discloses a water-saving backflow preventer structure, including a housing, a water inlet valve, a water outlet valve, a drain valve and a main valve stem located inside the housing, and an elastic sealing device. The sealing device divides the interior of the housing into two cavities, the main cavity and the control cavity, wherein the shell wall of the main cavity has three openings: water inlet, water outlet and water discharge. The water inlet valve, water outlet valve and the drain valve are respectively installed at these three openings, one end of the main valve rod is connected with the drain valve, and the other end is connected with the elastic sealing device; the water inlet valve includes a valve seat, a valve plate, Valve stem and reset device, two sealing l...

AI Technical Summary

Problems solved by technology

When the water inlet pressure fluctuates during normal water supply, it can prevent the intermittent opening of the drain valve. However, in practical applications, especially during normal water supply, the control chamber is directly connected to the main chamber. Under the action of ejection, it will cause the pressure in the control chamber to drop, and even cause the drain valve to open during normal water supply, which seriously affects the normal use

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