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Status and Characteristics of Gas Pipeline Valves
I. Status Quo and Prospects of China's Natural Gas Industry As China's long-term high-speed economic growth demands energy, people's demands for living quality and ecological environment are also on the rise. The centuries-long project of west-east gas transmission, east-west gas transmission and the introduction of Russian natural gas have shown that natural gas, an important source of energy with high quality, cleanliness and environmental protection, is being hitherto highly regarded by our government. China Gas has set up 46 joint ventures with natural gas franchises over a dozen provinces along the East-West Gas Pipeline and the East Sichuan Gas Pipeline to invest more than 50 natural gas pipelines projects, a figure that will increase with China Gas The rapid expansion of the market continues to increase. The successful implementation of the West-East natural gas transmission project has raised the level of China's natural gas pipeline network and laid the foundation for the formation of the national natural gas pipeline network. Starting from the West-East Gas Pipeline Project, China's natural gas pipeline construction gradually moves closer to the international advanced level and develops toward long-distance, large-caliber, high-pressure and highly automated network management, laying a solid foundation for the rapid development of China's natural gas industry basis. The construction of the West-East Gas Pipeline Project has opened up an energy artery running through our country. It is of great significance for promoting the development of the western region, accelerating the development of the central and western regions, benefiting the people of all ethnic groups in Xinjiang and the regions along the line, promoting industrial restructuring and energy structure optimization, Energy security will surely play a big role. West-East Gas Pipeline project from Lunan in Xinjiang west, via 10 provinces, autonomous regions and municipalities, a total length of about 4000 km, the design annual gas transmission 12 billion cubic meters. The ongoing transmission project has reached 17 billion cubic meters. The middle and lower reaches will build Liuzhuangzi, Jintan two large underground gas storage. Pipeline project through the Gobi Desert, the Loess Plateau, the Taihang Mountains, across the Yellow River, the Huaihe River, the Yangtze River, China is currently the largest diameter, the thickest pipe wall, the highest pressure level, the most technically difficult pipeline project to create a number of domestic natural gas pipeline Leading records, but also created the history of the world's high-speed pipeline construction. The completion and operation of the West-East Gas Pipeline Project symbolized the overall level of China's natural gas pipeline construction to a new level, laying the foundation for China's natural gas pipeline network. It is understood that our country will take the construction of the West-East Gas Pipeline as an opportunity to consider the natural gas resources in the eastern, central, western, offshore and terrestrial areas, actively implement the "going global" strategy, introduce natural gas resources from other countries, further improve our natural gas pipeline network development plan and accelerate Trunk pipeline, gas storage, booster stations and related branch lines to build a nationwide five horizontal and two vertical natural gas trunk pipe network, and gradually form the West-East Gas Pipeline, north gas south, near the outer supply, sea air landed gas supply The pattern will eventually form the main west-east gas transmission line from Lunan to Shanghai and Changqing to Beijing, the second Shaanxi-Beijing line as well as the second line of Shaanxi-Beijing line from Sichuan to Chongqing, the Beijing-Tianjin-Hebei-Shandong-Jinjiang River, the Yangtze River Delta, the northwest and the two lakes Of the regional natural gas pipe network, and ultimately the country's diversified natural gas resources, supply network and market scale. Second, the natural gas pipeline valve characteristics With the development of natural gas pipeline industry, the amount of natural gas pipeline valves are increasing, natural gas pipeline valves and ordinary valves are different. Specifically, the following points: 1, the material pipeline transportation of natural gas containing a large amount of hydrogen sulfide before desulfurization (which is a highly toxic and corrosive gas, which reacts with iron to produce iron sulfide, flaking off in the form of flakes, Erosion of machinery and equipment). Even after natural gas desulfurization process, there is still residual hydrogen sulfide. Therefore, select the pipeline valve corrosion-resistant materials to be selected anti-sulfur. 2, the amount of leakage Most of the natural gas pipe network built on the edge of the city, unlike the general operation and management of factories, workers often have the operation, maintenance and inspection. Ordinary city gas pipelines are over a hundred kilometers long and can only be patrolled and inspected on a regular basis. Sometimes the pipelines need to go through complicated areas and the loss of media may lead to a serious fire accident. In particular, the pipeline from the city closer to prevent leakage of the valve is particularly important. Gas valve leakage is very strict requirements, usually buried and more important valves are all welded body valve structure. In order to ensure the sealing performance of pipeline valves, sealing pair with excellent corrosion resistance, wear resistance, self-lubrication and flexibility. In recent years, the development of polymer materials for the selection of pipeline valve sealing material provides a vast selection of world, such as PTFE, Nylon, NBR, VITON and other special. 3, the application pipeline once put into operation, not allowed to stop running for a few years, the longer the operation the better, unlike the general chemical plant or refinery, overhaul period. Natural gas transported by the pipeline faces a large number of users in the whole city, and there are residents, enterprises, factories, and the like, and in particular, natural gas-based enterprise users are not allowed to have a brief interruption. Inline pipeline in the pipeline once the valve failure, the consequences could be disastrous. Therefore, the main sealing pipeline valve wearing parts such as valve seat and other parts require long life. General mainline pipeline valve life requirements of more than 30 years. 4, the drive due to high pipeline pressure, large diameter, fast switching time, pipeline valves need to use high-torque drive. Such as electric or pneumatic devices, gas-liquid linkage or electro-hydraulic linkage. Drive also have explosion-proof requirements, requiring EExd IIB T4, protection class IP68. Because of the management and control personnel in the station or the central control room, requiring pipelines in the event of a major accident such as rupture, pipeline valves can be automatically cut off. Pipeline valve requires a small operating force, in the temperature, the impact of changes in external forces, to achieve accurate operation. In particular, emergency shut-off valve, must be able to long-term in a fully open state, if necessary, quickly closed the pipeline. At the same time, require the valve opening and closing position and opening indicator accurate, easy to understand, to meet the appropriate switching speed.