Valves are an important part of the equipment manufacturing industry. They are indispensable fluid control equipment for pressure-bearing special equipment boilers, pressure vessels and pressure pipes. They are widely applied in: petroleum, chemical, power, long-distance pipelines, shipbuilding, nuclear industry, aerospace, onshore & offshore oil recovery, and other fields.With the development of cryogenic technology – liquid helium (LHe), liquid hydrogen (LH2), liquid nitrogen (LN2), liquid oxygen (LO2) and liquefied natural gas (LNG) are evolving in the fields of nuclear fusion energy, aerospace, petrochemical industry and daily life. The application in the field is becoming more and more extensive, and people put forward higher requirements on the performance of the cryogenic valve matched with the pipeline transportation system. Because the operating temperature of the cryogenic valve is extremely low [i.e. liquid helium (-268.9 ºC), liquid oxygen (-218.8 ºC), liquid hydrogen (-252 ºC), liquefied natural gas (-161.6 ºC), etc.], the design and manufacture of valves presents a series of serious technical challenges.Zhejiang is a large province for valve manufacturing, and the valve output value has accounted for nearly one-third of the total valve output value of the country. Although the backbone enterprises in the province have been able to design and manufacture various valves in accordance with international standards such as: ISO, DIN, and API. Some of the manufacturer’s products have reached the international advanced level and there is still a huge gap with foreign companies in the core technologies. Also, high-end valves still rely on imports.The Project of Natural Gas Transmission from West to East China is a very large-scale infrastructure for the construction of the country during the tenth five-year period. A large number of LNG (liquefied natural gas) Terminals are required to be built along the way. The LNG Terminal Phase I Project basically purchases cryogenic valves from foreign manufacturers such as South Korea S&S, American Flowserve, Spain Poyam, British Orton, Italian TAI, etc. Domestic valves are only purchased as spare parts.In recent years, the country has actively implemented the strategic measures for the localization of major equipment, which has brought a rare opportunity for the development of the valve manufacturing industry. The State Council issued a request to rely on key projects in the fields of high-efficiency clean power generation, natural gas pipeline transportation, liquefaction storage and transportation, and targeted domestic production of key products. Through investigation, it was found that the cryogenic valve is a cutthroat product of the above key projects.Against this background, RAYS Flow control, Inc. (RAYS) and Hefei Institutes of Physical Science, Chinese Academy of Sciences (CAS) have signed an Industry-University-Research collaboration agreement in March 2019 to implement the national innovation driving strategy. The agreement will carry out the following cooperation around the field of cryogenic valves:1. Research and development of new cryogenic valve materials;2. Development and application of cryogenic valve technology;3.Research on related science and technology projects;In summary, the two sides will make full use of the: talents, intellectual strengths, scientific research capabilities of CAS, market resources, and production conditions of RAYS. In order to play their respective roles, they share resources through technological innovation to promote technological progress and the transformation of scientific research achievement. With the management level, we will establish a close cooperation relationship between “production, study and research” to form a pattern of mutual promotion of research and industry, common development, and a win-win situation between industry & academia.The scientific research results brought by this cooperation will exert significant economic and social benefits and contribute to the development of China’s valve industry..slt {display:none}…

自现代工业革命以来，全球经济实现了迅猛发展。与此同时，人类付出了更为沉重的环境代价。随着温室气体排放量的增加，极端天气变得越来越常见，这似乎已成为人类无法逃避的命运。造成环境污染和温室效应的主要因素是工业排放到大气中的温室气体和污染物。为了减轻全球工业化进程对环境的影响，国际上已经实施了控制挥发性气体排放的策略，并形成了国际标准或规范。尽管一些发达国家在环境控制方面处于领先地位，但我们也发布了并实施了关于 FE 阀门的标准，并且越来越受到用户的认可。每隔两年，在全球工业领域就会举办“中国逃逸排放峰会”，分享他们在逃逸泄漏控制和 LDAR 实践方面的经验、技术和创新。正是由于发布了此类相关标准以及组织了相关活动，逃逸排放的标准化得到了更广泛的研究和发展。逸散排放是指在工业场所中设备出现意外或不真实的泄漏时，任何化学物质或化合物以任何物理形式逸散到大气中的情况。科学词典将逸散排放定义为由于泄漏、蒸发或风力作用而释放到大气中的污染物，以及与之相关的几个概念——例如有机化合物的低蒸发率。典型的化工厂泄漏源包括阀门（填料、法兰连接）、泵密封件、压缩机、法兰/接头以及安全/泄压装置。阀泄漏包括外部泄漏和内部泄漏。对于阀门而言，通常的泄漏评估标准是阀门的可见泄漏。然而，逸散排放严格指的是不可见泄漏，需要借助仪器进行检测，并且通常指的是填料区域和垫片区域的泄漏。填料区域一般是静密封，易于控制/扩散泄漏。而填料函区域是动态密封，阀杆的移动容易导致填料泄漏。一般来说，影响阀填料泄漏的主要因素如下：温度：这种填料在较高温度下具有比与其接触的金属部件更高的膨胀值，并且填料会被压缩。如果填料能在常温下通过逃逸试验，那么它也能在高温下通过逃逸试验（填充物本身的损耗率较小），因此填料很容易在首次常温测试和首次高温测试中都通过。如果从首次高温（400C）降至第二次室温测试时温度降低，填料的收缩量大于金属部件的收缩量，但填料的腔体与首次室温条件相比没有变化。理论上，石墨填料的体积也没有变化。然而，高温后，填料会有一定程度的燃烧损耗，所以填料内部会变得松散。然后填料的弹性会降低，高温降至常温后填料内部的压力也会降低。压板螺栓的扭矩会减小，这容易导致泄漏。然而，通过将该包装应用于室温下的扭矩值，原有的泄漏率能够得到满足。阀位公差：对影响填料泄漏试验的零件的形状和位置公差有以下要求：阀杆的直线度、阀盖和阀杆螺母的加工位置公差以及装配误差。误差的累积最终会导致阀杆相对于填料产生角度偏移。填料杆在往复运动中的侧压力不断变化，在侧压力较小的地方容易造成泄漏。此外，在阀杆进行一定次数的往复运动后，填料的连续挤压会使填料内孔的有效间隙变大，从而导致更容易泄漏。阀杆、填料压盖表面光洁度：阀杆和填料压盖表面越光滑，填料密封效果越好。填充有石墨的金属表面的微小不平整更容易实现密封。从满足密封和阀门制造要求的经济分析来看，阀杆的表面光洁度通常为 Ra0.4 - 0.6 微米，填料压盖的表面光洁度通常设定为 Ra1.6 - 3.2 微米。密封圈、阀杆间隙、填料密封圈以及密封圈间隙阀门的设计和制造应确保密封圈与阀杆之间的间隙大于填料密封圈与密封圈之间的间隙。这样做的目的是确保阀杆在移动过程中不会咬住密封圈。尽管密封圈与阀杆之间的间隙较小，填料密封效果更好，但密封圈与阀杆之间的间隙也不应过小。由于阀门的制造误差，间隙过小可能会导致阀杆咬住。由于存在填料端环，密封圈与阀杆之间的适当间隙不会导致填料超出标准范围泄漏。 注：原文中“packing gland”和“gland clearance”翻译为“填料密封圈”和“密封圈间隙”，较为准确地传达了原文的专业术语含义。其他翻译依据上下文和习惯进行调整。该阀门在使用过程中的环境影响是评估其性能的一个重要指标。其中，该阀门的逸散排放指数是评估其环保性能的一个重要参数。阀门的 FE（环境友好度）要求已成为阀门设计与制造的基本要求。2015 年，广泛应用于阀门行业的 API600 标准首次将 API624 内容纳入阀门的 FE 测试标准文本中。同时，中国国家标准（GB）也明确要求对加氢装置的阀门进行 FE 测试，依据的是 ISO15848 标准。ISO15848、VDI2440、API624、MESC SPE77/312 等均为在阀门领域广泛应用的 FE 标准。这些标准以氦气或甲烷气作为泄漏检测介质，并通过质子光谱法进行检测。其灵敏度通常为 10-12 帕·立方米·秒-1 。逃逸排放并非一个新话题。尽管社会对空气质量及环境问题的关注度持续升温，但近年来，石化行业在逃逸排放控制、泄漏检测及修复技术的应用方面才刚刚起步。毫无疑问，对逃逸排放测试与评估的要求推动了工业发展的不断进步。就阀门行业而言，加工精度和密封质量持续提升。因此，逃逸排放阀门将逐渐成为高端阀门市场的主流产品。…