A self-compensating cryogenic ball valve

Abstract

The invention discloses a self-compensation type low temperature ball valve. The low temperature ball valve comprises a top-mounted valve body, a valve cover mounted at the upper end of the valve body, a ball body arranged in an inner cavity of the valve body, valve bases arranged at the two sides of the ball body, and a valve rod embedded and connected to a square groove of the ball body, wherein the valve rod and the valve cover are formed to a spiral structure to apply additional pretightening force to the ball body; valve base rings are arranged between the valve bases and the ball body; the valve bases are lined on the valve base rings to enable the valve bases to be contacted with the ball body to form valve base seals; the ball body is set as a V-shaped ball body; the center of a flowing channel of the ball body and the center of the ball body have eccentricity in the vertical direction; the top, contacted with the valve rod, of the ball body is a plane structure; a filler sealing self-compensation device formed by a filler component is arranged between the valve rod and the valve cover; the bottom of the valve cover is set as a crotch opening structure; and the low temperature ball valve further comprises a valve base sealing self-compensation device accommodated in the crotch opening structure at the bottom of the valve cover. The low temperature ball valve, provided by the invention, is simple in structure, resists low temperature, and is strong in sealing performance.

Description

technical field [0001] The invention belongs to fluid control valve technology, in particular to a self-compensating low-temperature ball valve. Background technique [0002] The ball valve has simple structure, uniform sealing stress, reliable sealing, quick opening and closing, convenient maintenance and operation, so it is widely used. [0003] With the rapid development of petroleum, chemical and gas industries, especially the wide application of liquefied natural gas (LNG) as a new energy source, the demand for ultra-low temperature valves for LNG has increased rapidly. Since the temperature of LNG under normal pressure is -162°C, and it is flammable and explosive, when designing LNG ultra-low temperature valves, higher and stricter requirements are put forward for its sealing performance. At present, domestic cryogenic ball valves are still in the initial stage of development. For example, the cryogenic ball valves used in LNG stations basically rely on imports, which...

AI Technical Summary

Problems solved by technology

However, at low temperature, the expansion coefficient of non-metallic materials is much larger than that of metal materials, so that the shrinkage at low temperature is quite different from that of metal seals, valve bodies and other fittings, resulting in a serious decrease in the sealing specific pressure. with unsealable results

And most non-metallic materials will harden and become brittle at cryogenic temperatures, losing toughness, resulting in cold flow and stress relaxation

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