A cryogenic ball valve and method of using the same

Abstract

The invention relates to a cryogenic ball valve and a method for using the same. The cryogenic ball valve comprises a valve body, a valve cover, a ball body and a valve seat assembly; the ball body and the valve seat assembly are loaded into the valve body from an opening, and two valve seat assemblies are symmetrically arranged The two sides are respectively in sealing contact with the sealing surface on the valve body and the ball; the cryogenic ball valve is provided with a disc spring and an elastic block, which provide downward force and act on the ball and the valve seat respectively. On the assembly, the valve seat assembly and the ball body, the valve seat assembly and the valve body are tightly attached together, so as to achieve the sealing effect.

Description

technical field [0001] The invention belongs to the field of fluid control valves, and in particular relates to a cryogenic ball valve and a method for using the same. low temperature medium. Background technique [0002] In my country, ball valves are widely used in petroleum refining, long-distance pipelines, chemical and other industries. The ball valve is mainly used to cut off, distribute and change the flow direction of the medium in the pipeline. It can be closed tightly by rotating 90 degrees and a small torque. Generally, ball valves are suitable for switching and shut-off valves, so they need to have good sealing performance. [0003] The existing ball valve will open a large hole on the valve body, resulting in an uneven structure of the valve body, which is not a regular geometric body, and requires high dimensional accuracy, roughness and roundness of the sealing surface. At the same time, when the ambient temperature difference of the ball valve is large or ...

AI Technical Summary

Problems solved by technology

[0003] Existing ball valves will have a large hole in the valve body, resulting in uneven structure of the valve body, not a regular geometry, and high requirements for the dimensional accuracy, roughness, and roundness of the sealing surface

At the same time, when the temperature difference in the environment where the ball valve is located is large or when the low-temperature medium is transported, the valve body is cooled and causes a large amount of shrinkage, and due to the uneven structure or thickness of the valve body, the sealing surface of the valve body will produce serious irregular distortion, which will eventually lead to Seal failure of the valve body and seat assembly, prone to leakage

At the same time, the existing ball valves cannot be dynamically adjusted for different environmental temperature differences or the sealing pretightening force of the transport medium, and the valve adaptability is low

[0004] Secondly, the existing ball valve usually has a spring between the bonnet and the ball, resulting in a large local stress on the lower part of the ball and the lower part of the valve seat, uneven force on the entire ring of the valve seat, and uneven wear on the upper and lower ends of the valve seat. , after the valve is opened and closed for a certain period of time, the wear of the valve seat at 6 o'clock is more severe than that at 12 o'clock

When the elastic force provided by the spring on the ball is not enough to compensate for the uneven wear of the valve seat, the valve seat is prone to leakage

[0005] Furthermore, the pressure relief methods of existing ball valves usually have the following two methods: 1. By opening small pressure relief holes on the ball, the valve can only achieve one-way sealing, and the valve does not have two-way sealing; Pressure relief on the back of the seal, this pressure relief method is very unreliable, and it cannot be released to the designated end at the designated pressure. When the transport medium has a high expansion ratio, if the valve cavity cannot be released in time, the valve may be at risk of rupture

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