Quick automatic cut-off instrument valve

Abstract

The invention relates to an instrument valve, in particular to a quick automatic cut-off instrument valve. The bottom end of a valve rod is plugged in a flow passage hole at a valve cap end; the valve rod is separated from a valve clack; the valve clack is movably installed in a central flow passage hole; a flow passage hole at the valve cap end and a flow passage hole at a valve base end are provided on the valve body, and the diameters of the flow passage holes are less than that of the central flow passage hole on the valve body; the valve clack is in dynamic seal with the flow passage hole at the valve cap end and the flow passage hole at the valve base end to form a sealing pair; and the flow passage hole at the valve base end is communicated with a medium inlet and the flow passage hole at the valve cap end is communicated with a medium outlet to form a medium flow passage. The quick automatic cut-off instrument valve of the invention has simple operation and is cut off by front and back pressure difference of the detected medium rather than by field operating personnel. Maintaining personnel can maintain a display instrument without any treatments, and after the instrument is normal, the quick cut-off instrument valve is opened so that the front pressure and back pressure are in balance. The invention has the advantages of resource saving, environment protection, quick and convenient installation and use, on-line maintenance and safe and reliable operation of pipelines.

Description

Technical field [0001] The present invention relates to valves, especially instrument valves. Background technique [0002] At present, in the oil and gas pipeline control system in China, the valve in front of the instrument basically uses transmission [0003] The traditional installation method, that is, the use of ordinary instrument shut-off valves, which are connected by pipe joints, pipe joints and gaskets, not only are complicated and costly, but also have many potential leak points and large installation space. As long as there is leakage from a pipe joint, gasket or weld, when the control pipeline connected to the instrument leaks and a large amount of medium is sprayed, if you install an ordinary instrument valve, you can only rush to the site manually and manually close the instrument valve. However, in the petrochemical production and thermal power industry, there are many high temperature, high pressure, flammable, explosive and toxic and harmful media. In these high...

AI Technical Summary

Problems solved by technology

When high-temperature, high-pressure, highly toxic, flammable, and explosive media are sprayed, it is difficult for maintenance personnel to approach the accident site. They have to close the running pipeline and empty the medium for maintenance, which not only wastes resources but also pollutes the environment. In severe cases, it will cause heavy losses to people's lives and property

[0004] Foreign countries have done relatively well in this regard, and some manufacturers also produce globe valves that can be remotely controlled, such as the German "Herberholz" company. Some special-purpose globe valves they produce have electric, hydraulic or pneumatic transmission devices, which can Remote control, when the pipeline leaks, you can remotely operate the transmission, close the valve, and cut off the medium, but their product structure is complicated, the installation cost is high, and the price is expensive, and the internal parts are mostly made of Cr13 or austenitic stainless steel, austenitic stainless steel Although austenitic stainless steel has excellent corrosion resistance, it is not resistant to wear and affects the service life of the valve. Although Cr13 has high strength and hardness, its corrosion resistance is not as good as that of austenitic stainless steel, especially for some highly corrosive materials. Medium (such as: strong acid, strong alkali, high concentration hydrogen sulfide, etc.) cannot use Cr13 as the internal parts of the valve, so that their application is greatly restricted

[0005] In addition, the processing technology of the valve body also has a certain impact on the quality, because the diameter of the inner hole of the valve body is small and the operating space is limited, the common welding method is prone to welding defects, and the welding quality required for valve sealing cannot be achieved.

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