Dual-sphere one-way metal seal ball valve

Abstract

The invention discloses a dual-sphere one-way metal seal ball valve, belonging to the technical field of valves. According to the technical main points, the dual-sphere one-way metal seal ball valve comprises a valve body, wherein a medium inlet and a medium outlet are formed in two ends of the valve body along the axial direction respectively; an installation blind hole is formed in the valve body corresponding to the medium inlet along the axial direction; a first valve ball and a second valve ball are arranged in the installation blind hole from inside to outside separately; a first valve seat module is arranged between the outer wall of the first valve ball and the installation blind hole; a second valve seat module is arranged between the outer wall of the second valve ball and the installation blind hole; the first valve seat module comprises a first fixed valve seat and a first movable valve seat clamped on the outer wall of the first valve ball; the first fixed valve seat and the installation blind hole are in interference seal connection; the second valve seat module comprises a second fixed valve seat and a second movable valve seat clamped on the outer wall of the second valve ball; and the second fixed valve seat and the installation blind hole are in interference seal connection. The dual-sphere one-way metal seal ball valve disclosed by the invention is compact in structure, stable in work and long in service life, and is used for controlling of medium flow.

Description

technical field [0001] The invention relates to a ball valve, more specifically, to a double-ball one-way metal-sealed ball valve. Background technique [0002] Existing metal hard-sealed ball valves used under harsh working conditions of high-temperature and high-pressure media have high failure frequency, short service life, and are prone to failures such as internal leakage, external leakage, and jamming. Usually, the online running time of the metal hard seal under the harsh working conditions of high temperature and high pressure medium is about half a year at most, or even breaks down in two or three months, which directly affects the safety and economy of users. [0003] Disadvantages of metal hard-sealed ball valves under severe working conditions of high temperature and high pressure medium: [0004] 1) The sealing coating of the ball and the valve seat is easily damaged by the erosion of the medium, resulting in serious internal leakage and short service life [...

AI Technical Summary

Problems solved by technology

The service life of the ball and valve seat coating is not only affected by the coating process and quality, but also the erosion and damage of the coating by the medium is the main reason for the short life of the metal hard-sealed ball valve.

[0006]When the ball valve is opened, due to the large relative pressure difference between the upstream and downstream, the flow gap is small, and the flow rate is fast, the medium will have a strong impact on the secondary coating of the ball valve. With the continuous increase of the switching frequency of the ball valve, the erosion will increase, and the medium will peel off and corrode the sealing surface coating, which will eventually cause serious internal leakage of the ball valve.

[0007]2) External leakage occurs at the seal between the valve body and the valve cover

[0008]Usually, the metal hard seal ball valve body and valve cover are sealed by bolts pressing the gasket, but when used under high temperature and high pressure harsh conditions, the medium temperature, Alternating changes in pressure will cause leakage at the seal between the valve body and the bonnet

[0009]3) The metal hard-sealed ball valve is stuck

If the structural design does not consider the expansion compensation of the material at high temperature, the ball valve will be jammed and unable to operate

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