Double-membrane back pressure valve

Abstract

The invention discloses a double-membrane back pressure valve. The double-membrane back pressure valve comprises a valve body, a bonnet, a valve rod, a force measuring sensor, a spring, membranes, a damper, a display unit and the like and is characterized in that the upper membrane and the lower membrane are separated through a metal support piece to form a middle cavity, the spring and the damperare fixed on the upper membrane through a bottom plate, the upstream position of the lower membrane is provided with a small hole. When the double-membrane back pressure valve is used, a hand wheel is rotated to allow the valve rod to move downwardly, and the valve is closed; when fluid pressure is larger than a set value, the membranes upwardly compress the spring, the back pressure valve is opened, and fluid start flowing; when the fluid pressure is smaller than a set value, the spring pushes the membranes downwardly to close the back pressure valve, and fluid flowing is stopped. The double-membrane back pressure valve has the advantages that by the small hole, the fluid pressure is transmitted into the cavity between the two membranes, the upper membrane is uniformly stressed, the stress of the membranes, the spring and the damper is relatively balanced, and valve movement stability is achieved; by the damper, gentle valve movement is achieved, and disturbance to the flowing is reduced.

Description

technical field [0001] The invention relates to the technical field of flow control valves, in particular to a double diaphragm back pressure valve. Background technique [0002] The function of the back pressure valve is to maintain the required pressure in the pipeline so that the pump in the pipeline can output the flow normally. For example, for volumetric pumps such as metering pumps, excessive delivery will occur when working under low pipeline pressure. In order to prevent this problem, it is necessary to have a certain back pressure at the outlet of the metering pump. Generally, a back pressure valve is installed at the outlet of the metering pump. achieve this purpose. [0003] The structure of the traditional back pressure valve is similar to that of the one-way flow valve. The pressure control is realized by the built-in spring. When the fluid pressure in the pipe is lower than the set pressure, the diaphragm closes the valve under the action of the spring force....

AI Technical Summary

Problems solved by technology

[0004] The traditional back pressure valve has many turns in the flow channel, so the flow loss is relatively large

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