Spring full lift safety valve against back pressure

Abstract

The invention relates to a spring full lift safety valve against back pressure. The spring full lift safety valve against the back pressure comprises a valve body, a valve clack, a valve seat, a valvecover, a valve rod and a spring pressure setting device, wherein a sealing surface matched with the valve seat is arranged at the center of the lower end face of the valve clack, an inlet channel ofthe valve body is concentric with the valve rod, and the center line of an outlet channel is perpendicular to the center line of the valve rod. The spring full lift safety valve against the back pressure is characterized in that the upper side of the sealing surface of the valve seat communicates with the inlet channel of the valve body, and the lower side of the sealing surface of the valve seatcommunicates with the outlet channel of the valve body; and an annular channel is formed between the outer circumference of the sealing surface of the valve seat and the inner circular wall of the inlet channel of the valve body, and a pressure cavity is formed by the annular lower end face of the outer side of the sealing surface of the valve clack and the annular channel. According to the springfull lift safety valve against the back pressure, the valve clack has no back pressure, the pressure fluctuation in the outlet channel of the valve body does not affect a setting pressure value of the spring pressure setting device, the opening pressure of the valve clack is equal to the setting pressure value, and the spring full lift safety valve against the back pressure has the advantages ofaccurate opening, stable pressure and good protection performance for pressure vessels or pipelines.

Description

technical field [0001] The invention belongs to the field of valves, in particular to a spring type safety valve. Background technique [0002] Spring safety valves are widely used in pressure control valves for pressure vessels and pipelines. Its structure includes a valve body, a valve disc, a valve cover, a valve stem, and a pressure setting device. The pressure setting device uses a spring device. For example, the spring type safety valve with the announcement number CN203500596U has a hard-soft dual-mass seal structure, which is mainly connected by a valve seat, a guide valve sleeve, a recoil disc, an inner shaft of the valve disc, and a cover of the valve disc, which are assembled in the safety valve body. The combined disc is composed of a hard alloy convex ring welded on the bottom surface of the combined valve disc and a convex sealing gasket embedded in it to form a tight hard and soft dual-mass sealing structure with the top surface of the valve seat respectively....

AI Technical Summary

Problems solved by technology

However, when this kind of spring safety valve is used in the condition of back pressure at the outlet end of the valve body, the back pressure in the outlet pipe of the valve body and the spring jointly generate downward pressure on the disc, because the pressure in the outlet pipe of the valve body is easy to Unstable fluctuations lead to unstable opening pressure of this spring safety valve, and when the back pressure is large, the disc cannot be opened, and the safety protection performance is poor

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