Top-mounted ball valve

Abstract

The invention relates to a top-mounted ball valve. The top-mounted ball valve comprises a fixer positioned between a ball body and a valve body, wherein the fixer is sealed together with the ball body; a sealing element is arranged between the fixer and the valve body; a limiting piece is arranged between the valve body and the fixer; the outer circumferential surface of the limiting piece is in threaded connection with the valve body; the limiting piece is connected with the fixer in an anti-rotation way. By rotating the fixer and moving the limiting piece towards the fixer, a sealing gap can be formed between the limiting piece and the fixer for preventing the sealing element from moving. The distance between the fitting surface of the fixer and the sealing element and the axis of the valve body is smaller than the distance between the sealing surface of a sealing material and the axis of the valve body, and the distance between the fitting surface of the valve body and the sealing element and the axis of the valve body is larger than the distance between the center of the sealing surface of the sealing material and the axis of the valve body. Pressure is introduced into the end of the ball valve, the fixer is pressed against the ball body through the pressure difference between both sides of the fixer, pressure is introduced into a middle cavity, the fixer is pressed against the ball body through the pressure difference between both sides of the fixer, and the sealing element is prevented from moving, thereby realizing a reliable bidirectional sealing effect between the fixer and the valve body.

Description

technical field [0001] The invention relates to the technical field of valve manufacturing, in particular to a top entry ball valve. Background technique [0002] Ball valve has become one of the most widely used valves due to its reliable sealing, simple structure and convenient maintenance. Compared with the side-entry ball valve, the top-entry ball valve has the advantages of fewer external leakage points and less influence of pipeline stress on it. At the same time, the top-entry ball valve is widely used because it can realize convenient online maintenance. Among the top-entry ball valves, DBB and DIB are two types of seat functions. Among them, the DBB seat is also called a single-piston effect seat. Each seat can resist the force in one direction and discharge the middle cavity. DIB valve seat is divided into DIB-1 valve seat and DIB-2 valve seat. Each valve seat of DIB-1 valve seat resists two directions of force, which is called double piston effect valve seat, b...

AI Technical Summary

Problems solved by technology

[0006] For this reason, the technical problem to be solved by the present invention is that in the prior art, the ball valve capable of realizing bidirectional sealing has a short service life and poor sealing reliability due to the movement of the sealing element, while the valve seat assembly structure capable of realizing the fixed sealing element can only realize unidirectional sealing Therefore, by rationally designing the structure of the valve seat assembly, a ball valve that can prevent the seal from moving and achieve bidirectional reliable sealing can be provided.

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