原文：
阀门基本知识，阀门是用以控制流体流量、压力和流向的装置。被控制的流体可以是液体、气体、气液混合体或固液混合体。阀门通常由阀体、阀盖、阀座、启闭件、驱动机构、密封件和紧固件等组成。阀门的控制功能是依靠驱动机构或流体驱使启闭件升降、滑移、旋摆或回转运动以改变流道面积的大小来实现的。 阀门基本知识，阀门的用途很广泛，它与人们的日常生活有密切的关系，例如自来水管用的水龙头、液化石油气灶用的减压阀都是阀门。阀门也是各种机械设备如内燃机、蒸汽机、压缩机、泵、气压传动装置、液压传动装置车辆、船舶和飞行器中不可缺少的部件。 　 公元前两千多年前，中国人就在输水管道上使用了竹管和木塞阀，以后又在灌溉渠道上使用水闸，在冶炼用的风箱上使用板式止回阀，在井盐开采方面使用竹管和板式止回阀提取盐水 随着冶炼技术和水力机械的发展，在欧洲出现了铜制和铅制旋塞阀。随着锅炉的使用，1681年又出 现了杠杆重锤式安全阀。1769年瓦特蒸汽机出现以前，旋塞阀和止回阀一直是最主要的阀门。 蒸汽机的发明使阀门进入了机械工业领域。在瓦特的蒸汽机上除了使用旋塞阀、安全阀和止回阀外， 还使用了蝶阀，用以调节流量。随着蒸汽流量和压力的增大，使用旋塞阀控制蒸汽机的进汽和排汽已不 能满足需要，于是出现了滑阀。 1840年前后，相继出现带螺纹阀杆的截止阀，和带梯形螺纹阀杆的楔式闸阀，这是阀门发展中的一 次重大突破。这两类阀的出现，不仅满足了当时各种工业对压力、温度不断提高的要求，而且初步满足 了对流量调节的要求。此后随着电力工业、石油工业、化学工业和造船工业的发展，各种高中压阀门得到迅速发展。 　 第二次世界大战后，由于聚合材料、润滑材料、不锈钢和钴基硬质合金的发展，古老的旋塞阀和蝶阀获得了新的应用，球阀和隔膜阀得到迅速发展。截止阀、闸阀和其他阀门品种增加，质量提高。阀门制造业逐渐成为机械工业的一个重要部门。阀门按使用功能可分为截断阀、调节阀、止回阀、分流阀、安全阀、多用阀六类。 　 截断阀主要用于截断流体通路，包括截止阀、闸阀、旋塞阀、球阀、蝶阀隔膜阀、夹管阀等；调节阀主要用于调节流体的压力、流量等，包括调节阀、节流阀、减压阀和浮球调节阀等；止回阀用于阻止流体的逆向流动；分流阀用于分配流体的通路去向，或将两相流体分离，包括滑阀、多通阀、疏水阀和排空气阀等；安全阀主要用于安全保护，防止锅炉、压力容器或管道因超压而破坏；多用阀是具有一种以上功能的阀门，如截止止回阀既能起断流作用又能起止回作用。 　 工业管道阀门按公称压力又可分为真空阀、低压阀、中压阀、高压阀、超高压阀；阀门按工作温度又可分为常温阀、中温 阀、高温阀、低温阀；阀门还可按驱动装置的类型、与管道的联接方式和阀体的使用材料等进行分类。阀门可按各种分类方法单独地或组合地命名，也可按启闭件的结构特征或具体用途命名. 　 阀门的基本参数是工作压力、工作温度和口径。对于大量使用于工业管道的各种阀门，常用公称压力和公称通径作为基本参数。公称压力是指某种材料的阀门，在规定的温度下，允许承受的{zd0}工作压力。公称通径是指阀体与管子联接端部的名义内径。 阀门根据其种类和用途有不同的要求，主要有流通、密封、调节、强度、启闭等性能。在设计和选用阀门时，除了要考虑基本参数和性能外，还要考虑流体的性能，包括流体的相态(气体、液体或含固体颗粒)、腐蚀性、粘度、毒性、易燃易爆性，贵重稀有程度和放射性等。 　 密封性能和强度性能是一切阀门最基本、最重要的性能。阀门的密封分内密封和外密封两部分。内密封是阀瓣与阀座之间的密封；外密封是阀杆运动部位与阀盖之间、阀体与阀盖之间和阀体与管道联接部位之间的密封。阀门在使用时不仅要求密封性能好，而且必须保证安全。 　 如果因密封不好而发生泄漏或因强度不够而使零件破坏，将会造成不同程度的经济损失，如输送有 毒、易燃易爆或有强腐蚀性流体，还可能导致严重的安全事故。为了保证阀门的密封和强度，除了必须 遵守有关标准规定合理地进行结构设计、确保工艺质量外，还必须正确地选用材料。 通用阀门，低压非腐蚀性流体用的阀门使用铸铁或铸铜；高、中压阀用铸钢或锻钢；高温或高压阀使用合金钢；用于腐蚀性流体的阀门用不锈钢、塑料，耐蚀合金(如铜镍钼合金、钛合金和铅合金等)或用铸铁 、铸钢内衬耐蚀材料制造。 通常阀门，低压阀的密封面大多使用黄铜或青铜，高、中压阀大多使用不锈钢，要求较高的高、中压阀或高温阀等使用钴基硬质合金。聚合材料在阀门中已获得广泛应用，如球阀的阀座主要采用聚四氟乙烯塑料，蝶阀的密封圈和隔膜阀的隔膜采用各种橡胶材料。这些材料在可以使用的温度范围内具有比金属更好的密封性。 　随着现代核工业、石油化学工业、电子工业和航天工业的发展，以及流程工艺自动控制和远距离流体输送的发展，促进了现代低温阀、真空阀、核工业用阀和各种调节阀的发展。用于远距离控制和程序控制的阀门驱动装置的应用越来越多。 　 阀门的发展将向扩大产品参数，发展节能、省力和自控阀门，改进结构、采用新材料和新工艺，提高阀门的使用寿命，以及发展专用阀门系列等发面发展，如用于液氧、液氢和液化天然气等的低温阀、真空阀、核工业用阀、安全阀、调节阀、疏水阀和阀门驱动装置等。

“ The history of the valve ”是由提供的阀门新闻，译文仅供参考。另外，中国止回阀网还提供相关产品搜索： 、 、 、 、 等。

译文：
Basic knowledge of the valve, the valve is used to control fluid flow, pressure and flow devices. The fluid can be controlled is a liquid, gas, gas-liquid mixture or liquid mixture. Valves are usually made up of body, bonnet, seat, hoist parts, drive mechanism, seals and fasteners and other components. Control valves or fluid drive mechanism is driven to rely on pieces of lifting hoist, sliding, rotating or turning motion put to the size of change in flow area to achieve. Basic knowledge of the valve, the valve is so widely used, it is with people's daily lives are closely related, for example, useful water faucet, valve LPG stoves are used in the valve. Valve is also the machinery and equipment such as internal combustion engines, steam engines, compressors, pumps, pneumatic actuators, hydraulic power units of vehicles, ships and aircraft components indispensable. BC 2000 years ago, the Chinese had used the water pipe valve bamboo and cork, and later use in irrigation channels gate, bellows used in refining the use of plate check valve, in the use of well salt mining Extraction of salt water bamboo and plate check valves and hydraulic machinery as smelting technology development in Europe, copper and Lead plug. With the use of boilers, 1681, has emerged lever hammer safety valve. Watt steam engine in 1769 before the advent of plug valves and check valves have been the main valve. The invention of steam engine valve into the mechanical industry. Watt's steam engine in addition to using the plug, valve and check valve, but also use the butterfly valve to regulate flow. As the steam flow and pressure, using the plug into the control of the steam engine and the exhaust gas can not meet the need, so there slide valve. 1840, one after another with a threaded stem of the cut-off valves, and valve stem with a trapezoidal thread wedge gate valve, valve development is a major breakthrough. The emergence of these two types of valve, not only to meet a variety of industries at the time the pressure, temperature, increasing requirements and to meet the initial requirements for flow regulation. Since then with the power industry, petroleum industry, chemical industry and shipbuilding industries, all the rapid development of high pressure valves. After World War II, as polymeric materials, lubricants, steel and cobalt-based alloy development, the old plug and butterfly was a new application, globe and diaphragm valves are developing rapidly. Valves, gate valves and other valves varieties increased quality. Valve manufacturing machinery industry has become an important sector. Valve-per-use features can be divided into cut-off valve, control valve, check valve, diversion valve, safety valve, Multi-valve six. Cut off cut-off valve is mainly used for fluid pathway, including the cut-off valve, gate valve, plug valve, ball valve, butterfly valve diaphragm control valve folder; the main control valve for regulating fluid pressure, flow, including the control valve, section flow valves, pressure reducing valves and float valves, etc.; check valve used to prevent the reverse flow of fluid; shunt valve fluid channel for distribution of destination, or two-phase separated, including the slide valve, multi-valve, hydrophobic valves and drain valves, etc.; valve is mainly used for security, to prevent the boiler, pressure vessel or pipeline overpressure due to the damage; multi-purpose valve is a valve with more than one function, such as the cut-off valve not only from the stop can return to the role of the role of beginning and end. Industrial pipe valves by nominal pressure can be divided into the vacuum valve, low pressure valve, the pressure valve, high pressure valves, high pressure valve; valve by valve temperature can be divided into normal temperature, the temperature valve, high temperature valve, cryogenic valve; valve gate drive device can also type in accordance with the pipe connection methods and the use of body materials are classified. Valve can be of various classification methods alone or in combination to name, but also can open and close parts of the structural characteristics or specific purposes named. The basic parameters of the valve is working pressure, temperature and diameter. For large-scale use in industrial pipeline valves, commonly used nominal pressure and nominal diameter as the basic parameters. PN is a material of the valve, the required temperature, to allow maximum exposure to work stress. Nominal diameter pipe is connected with the body on behalf of end diameter. Valve according to the types and uses have different requirements, mainly in circulation, sealing, adjusting, strength, open and close properties. In the design and selection valve in addition to considering the basic parameters and properties, but also consider the performance of fluid, including fluid phase (gas, liquid or solid particles containing), corrosion, viscosity, toxic, flammable Easy explosive, and radioactive and other precious rarity. Sealing performance and strength properties of all the valve most fundamental and important performance. Valve seal and the outer sealing alternative for sealing two parts. Is within the seal between the valve flap and valve seat seal; outer seal is part of the stem movement and the valve cover, valve body and valve cover and valve body parts and the seal between the pipe connection. Valve in use not only requires good sealing performance, and must ensure safety. If due to seal leaks or bad but strong enough Ershi parts damaged, it will result in different levels of economic losses, such as the transportation of toxic, flammable or corrosive fluids, can also lead to serious security incidents. To ensure the valve seal and strength, in addition to observe the standards of rational structural design requirements to ensure process quality, but also must be properly selected materials. General valve, low-pressure valves used in non-corrosive fluid to use cast iron or bronze; high pressure valve in cast steel or forged steel; high temperature or high pressure valves used alloy steel; for corrosive fluid valve of stainless steel, plastic, corrosion resistant alloy (such as copper and nickel molybdenum alloys, titanium alloys and lead alloys, etc.) or cast iron, cast steel liner corrosion material. Usually the valve, low pressure valve sealing surface usually use brass or bronze, high, medium pressure valve mostly stainless steel, require a higher high, medium and high pressure valve or valve using cobalt-based alloy. Polymeric materials in the valve has been widely used, such as ball valve seat mainly PTFE plastic, butterfly valves and diaphragm seal with a variety of rubber diaphragm material. These materials can be used in the temperature range and better than the metal seal. With modern nuclear industry, petrochemical industry, electronic industry and aerospace industry, and process automation technology and the development of long-distance fluid transport, the promotion of modern cryogenic valves, vacuum valves, nuclear valves and a variety of industrial control valves development. For remote control and process control valve actuator applications is increasing. Valve will extend the product development parameters, the development of energy-saving, labor-saving and automatic control valves, improved the structure of new materials and new techniques to increase valve life, and the development of specific valve series are failing to develop, such as for liquid oxygen, liquid hydrogen and liquefied natural gas, low temperature valve, vacuum valve, the nuclear industry with a valve, safety valve, control valve, steam trap and valve actuator and so on.