LNG ultra-low temperature top-mounting type ball valve seat capable of achieving pre-tightening force fine tuning and on-line disassembling

Abstract

The invention discloses an LNG ultra-low temperature top-mounting type ball valve seat capable of achieving pre-tightening force fine tuning and on-line disassembling. The LNG ultra-low temperature top-mounting type ball valve seat is characterized in that valve seat bearings are symmetrically arranged at the position, located on the upstream side and the downstream side of a valve element ball, in a valve body, and a locating pin is arranged between the end faces of the tails of the valve seat bearings and the front end face of a valve seat fixing ring; a valve seat sealing ring is embedded in twisting edges of the front ends of the valve seat bearings; valve seat pressing rings matched with the valve seat bearings in a threaded mode are arranged on the peripheries of the valve seat bearings, pre-tightening compressed springs are arranged between the tails of the valve seat pressing rings and the valve body, and the valve seat bearings can move in the axis direction by rotating the valve seat pressing rings. The LNG ultra-low temperature top-mounting type ball valve seat can be suitable for meeting requirements of LNG actual using conditions, the requirements for on-line maintenance, automatic decompression of a middle cavity in time and safe and reliable sealing performance are met, and quality and safety of LNG projects are guaranteed.

Description

technical field [0001] The invention is used for ultra-low temperature top-mounted ball valves in the field of liquefied natural gas (LNG), and is mainly used for cutting off or adjusting LNG medium. On the premise of ensuring the online maintenance of LNG valves, the reliable sealing performance is realized by fine-tuning the pretightening force of the valve seat. , and through the self-relieving pressure of the valve seat to the upstream of the pipeline, the danger of explosion caused by the overpressure of LNG gasification in the valve cavity is avoided. Background technique [0002] The liquefied natural gas (LNG) industry is a key industry in the petrochemical field and a key industry in energy strategy. With the development of industry, this industry has been paid more and more attention by the state and society, and its output is growing at a high speed of about 12% per year, becoming one of the fastest growing energy industries in the world. As we all know, the boil...

AI Technical Summary

Problems solved by technology

However, this structural form can only be installed in the top installation in the factory. After the ball valve is installed on the pipeline, the process groove on the valve seat will lose its function, and the online maintenance of the valve cannot be truly realized.

[0005] 3. The top-mounted valve body structure adopts the structure of split valve seat, and adopts chain connectors or threaded connections to connect the valve seat into a whole. Although online maintenance can be realized, the form of upstream valve seat and downstream valve seat Basically the same, when the upstream valve seat seal fails, the downstream valve seat cannot achieve effective sealing, or when the cavity is overpressured, the pressure is released to the upstream and downstream at the same time, and the entire valve cannot achieve safe and reliable sealing

[0006] Practice has shown that if LNG cryogenic ball valves that cannot meet the requirements of online maintenance, timely and automatic pressure relief in the middle cavity, and safe and reliable sealing performance are applied to actual projects, it will bring huge safety hazards and economic losses to the entire LNG project.

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