Valve seat structure for gate valve

Abstract

The invention discloses a valve seat structure for a gate valve. The valve seat structure for the gate valve comprises a valve body, a valve seat, a sealing ring, a gate plate and a valve rod. The bottom end of the valve rod is connected with the head of the gate plate, a valve body seat hole is formed in the valve body, the valve seat is mounted in the valve body seat hole of the valve body, the mutual connecting surfaces of the valve seat and the gate plate are arranged to be mutually matched metal surfaces, and a metal sealing surface is formed. An annular groove for containing the sealing ring is formed in the surface, in contact with the gate plate, of the valve seat. The small end of the sealing ring is arranged in the annular groove of the valve seat in a press-in mode, and the large end of the sealing ring is located between the metal surfaces of the valve seat and the gate plate to form an elastic sealing surface. The large end of the section of the sealing ring is provided with two symmetric wing angles, and a concave arc surface is arranged between the two wing angles so that the elastic deformation capacity of the wing angles can be improved. The outer diameter of the wing angles is larger than that of the annular groove. The valve seat structure for the gate valve has dual sealing functions of an elastic body to metal and metal to metal, and the valve can have blocking and discharging functions.

Description

technical field [0001] The invention relates to a valve seat structure of a gate valve, in particular to a valve seat structure with double sealing functions of elastic body to metal and metal to metal, so that the valve has double blocking and releasing functions. Background technique [0002] Gate valves are widely used in various fields such as petroleum, chemical industry, steel, metallurgy, electric power and natural gas. They are used as opening and closing devices to connect or cut off the medium in the pipeline. [0003] Analyzing the sealing principle of traditional gate valves, we found that in general industrial systems, most of the usual gate valve design calculations are based on single-sided forced sealing, that is, relying on medium pressure to press the sealing surface of the gate plate to the valve seat on the other side To ensure the sealing of the sealing surface. Due to the force of the valve stem, the same sealing specific pressure is formed on the inle...

AI Technical Summary

Problems solved by technology

However, due to the effect of the medium force, the specific pressure between the sealing pairs at the inlet end decreases and the specific pressure at the outlet end increases. Therefore, for a single-sided forced seal, the force of the valve stem can only ensure that the outlet end has sufficient sealing specific pressure, and the outlet end has a sufficient sealing specific pressure. The inlet end is not guaranteed to be sealed

However, the structure of the traditional valve seat inlaid with soft materials is mostly a press-in seal ring with a rectangular cross section, which has no elasticity and cannot use the medium force in the pipeline.

This kind of situation virtually limits the scope of use of the gate valve, and it is easy to cause the middle chamber parts to be corroded by the pipeline medium, reduce the service life of the valve middle chamber parts, and easily cause the valve to leak

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