Ultra-low-temperature top entry ball valve and assembly method thereof

Abstract

The invention discloses an ultra-low-temperature top entry ball valve and an assembly method thereof. The ball valve comprises a valve body, a valve cover, a valve rod and an operation mechanism, wherein the valve cover is connected with the valve body in a dismountable manner; a valve ball and a valve holder are arranged in a valve-body middle cavity of the valve body; the lower end of the valve rod penetrates through the valve cover and is connected with the valve ball; a drain board is welded to the valve cover; a steam cavity is arranged in the valve cover; a first pressure relief hole is formed in the valve rod; a second pressure relief hole is formed in the valve ball; the steam cavity, the first pressure relief hole and the second pressure relief hole are communicated with each other; a positioning ring, a positioning pin, an oblique triangular graphite sealing ring, a first lip-shaped sealing ring, a second lip-shaped sealing ring, a pressing ring, a disc spring, a threaded sleeve and an anti-rotation screw are arranged between the inner wall surface of the valve body and the valve holder; the anti-rotation screw penetrates through a positioning member and is connected with a threaded hole of the threaded sleeve; a valve holder sealing ring is fixedly arranged on the valve body and tightly presses the outer surface of the valve ball. Through the technical scheme, the ball valve disclosed by the invention is reasonable in structural design, simple in structure, good in sealing property, safe and reliable in use, and long in service life.

Description

technical field [0001] The invention relates to the technical field of ball valves, in particular to an ultra-low temperature top entry ball valve and an assembly method thereof. Background technique [0002] Top entry valve balls are widely used in oil and natural gas pipelines, and in oil recovery, oil refining, petrochemical, chemical, chemical fiber, metallurgy, electric power, nuclear power, food and paper making and other devices. The top-entry valve ball is easy and quick to disassemble on the pipeline, and the maintenance is convenient and quick. When the valve fails on the pipeline and needs to be repaired, it is not necessary to disassemble the valve from the pipeline, only the flange bolts and nuts need to be removed, the valve cover and stem assembly are removed from the valve body, and then the ball and seat are taken out assembly. The ball and the valve seat can be repaired online, which saves time and minimizes the loss in production. The ultra-low temperat...

AI Technical Summary

Problems solved by technology

The seal between the valve seat and the valve ball of the existing product adopts a single rigid seal. In an ultra-low temperature environment, different parts will be affected by the low temperature and will have a certain deformation, which makes the seal of the product unreliable; and the valve body structure is set If it is unreasonable, it will cause condensed water to enter the insulation layer and shorten the service life of the packing and the entire valve ball

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