原文：
蝶阀是用圆形蝶板作启闭件并随阀杆转动来开启、关闭和调节流体通道的一种阀门。蝶阀的蝶板安装于管道的直径方向。在蝶阀阀体圆柱形通道内，圆盘形蝶板绕着轴线旋转，旋转角度为0°~90°之间，旋转到90°时，阀门则牌全开状态。 蝶阀的发展历史 30年代，美国发明了蝶阀，50年代传入日本，到60年代才在日本普遍采用，而在我国推广则是70年代后的事了。目前世界上一般在DN300毫米以上蝶阀已逐渐代替了闸阀。蝶阀与闸阀相比有开闭时间短，操作为矩小，安装空间小和重量轻。以DN1000为例，蝶阀约2T，而闸阀约3.5T，且蝶阀易与各种驱动装置组合，有良好的耐久性和可靠性。 橡胶密封蝶阀缺点是作节流使用时，由于使用不当会产生气蚀，使橡胶座剥落、损伤等情况发生。为此，现在国际上又开发金属密封蝶阀，气蚀区减小，近几年我国也开发了金属密封蝶阀，在日本近年来还开发耐气蚀、低振动、低噪声的梳齿形蝶阀。 一般密封座的寿命在正常情况下，橡胶15年-20年，金属的80年-90年。但如何正确选用则要根据工况要求。 蝶阀的开度与流量之间的关系，基本上呈线性比例变化。如果用于控制流量，其流量特性与配管的流阻也有密切关系，如两条管道安装阀门口径、形式等全相同，而管道损失系数不同，阀门的流量差别也会很大。 如果阀门处于节流幅度较大状态，阀板的背面容易发生气蚀，有损坏阀门的可能，一般均在15°外使用。 蝶阀处于中开度时，阀体与蝶板前端形成的开口形状以阀轴为中心，两侧形成完成不同的状态，一侧的蝶板前端顺流水方向而动，另一侧逆流水方向而动，因此，一侧阀体与阀板形成似喷嘴形开口，另一侧类似节流孔形开口，喷嘴侧比节流侧流速快的多，而节流侧阀门下面会产生负压，往往会出现橡胶密封件脱落。 蝶阀和蝶杆本身没有自锁能力，为了蝶板的定位，要在阀杆上加装蜗轮减速器。采用蜗轮减速器，不仅可以使蝶板具有自锁能力，使蝶板停止在任意位置上，还能改善阀门的操作性能。 蝶阀操作力矩，因开度及阀门启闭方向不同其值各异，卧式蝶阀，特别是大口径阀，由于水深，阀轴上、下水头差所产生的力矩也不容忽视。另外，阀门进口侧装置弯头时，形成偏流，力矩会有增加。阀门处于中间开度时，由于水流动力矩起作用，操作机构需要自锁。 　蝶阀结构简单，只由少数几个零件组成，材料耗用省；体积小、重量轻、安装尺寸小，驱动力矩小，操作简便、迅速，只需旋转90°即可快速启闭；并且还同时具有良好的流量调节功能和关闭密封特性，在大中口径、中低压力的使用领域，蝶阀是主导的阀门形式。蝶阀处于xx开启位置时，蝶板厚度是介质流经阀体时{wy}的阻力，因此通过该阀门所产生的压力降很小，故具有较好的流量控制特性。蝶阀有弹密封和金属的密封两种密封型式。弹性密封阀门，密封圈可以镶嵌在阀体上或附在蝶板周边。 　采用金属密封的阀门一般比弹性密封的阀门寿命长，但很难做到xx密封。金属密封能适应较高的工作温度，弹性密封则具有受温度限制的缺陷。 如果要求蝶阀作为流量控制使用，主要的是正确选择阀门的尺寸和类型。蝶阀的结构原理尤其适合制作大口径阀门。蝶阀不仅在石油、煤气、化工、水处理等一般工业上得到广泛应用，而且还应用于热电站的冷却水系统。 　常用的蝶阀有对夹式蝶阀和法兰式蝶阀两种。对夹式蝶阀是用双头螺栓将阀门连接在两管道法兰之间，法兰式蝶阀是阀门上带有法兰，用螺栓将阀门上两端法兰连接在管道法兰上。 阀门的强度性能是指阀门承受介质压力的能力。阀门是承受内压的机械产品，因而必须具有足够的强度和刚度，以保证长期使用而不发生破裂或产生变形。 随着防腐合成橡胶和聚四氟乙烯的应用，蝶阀的性能得以提高，并满足于不同的工况条件。近十几年来，金属密封蝶阀发展迅速，随着耐高温、耐低温、耐强腐蚀、耐强冲蚀、高强度合金材料在蝶阀中的应用，使 金属密封蝶阀在高温、低温、强冲蚀等工况条件下得到广泛的应用，并部分取代了截止阀、闸阀和球阀。 蝶阀的结构特点 蝶阀具有结构简单、体积小、重量轻、材料耗用省，安装尺寸小，开关迅速、90°往复回转，驱动力矩小等特点，用于截断、接通、 调节管路中的介质，具有良好的流体控制特性和关闭密封性能。 蝶阀可以运送泥浆，在管道口积存液体最少。 低压下，可以实现良好的密封。 调节性能好。 蝶板的流线形设计，使流体阻力损失小，可谓是一种节能型产品。 阀杆为通杆结构，经过调质处理，有良好的综合力学性能和抗腐蚀性，抗擦伤性。蝶阀启闭时阀杆只作旋转运动而不作升降运行，阀杆的填料不易破坏，密封可靠。与蝶板锥销固定，外伸端为防冲出型设计，以免在阀杆与蝶板连接处意外断裂时阀杆崩出。 连接方式有法兰连接、对夹连接、对焊连接及凸耳对夹连接。 驱动形式有手动、蜗轮传动、电动、 气动、液动、电液联动等执行机构，可实现远距离控制和自动化操作。

“ Overview of metal hard seal butterfly valve ”是由提供的阀门新闻，译文仅供参考。另外，中国蝶阀网还提供相关产品搜索： 、 、 、 、 、 等。

译文：
Butterfly valve is used for opening and closing pieces of circular disc and the turning of the stem to open, close and adjust a valve fluid channel. Butterfly valve panels installed on the pipe diameter direction. Cylindrical channel in the valve body, disc-shaped disc around the axis of rotation, rotation angle 0 ° ~ 90 ° between the rotation to 90 °, the valve is open all license conditions. History of development of butterfly 30 years, the United States invented the butterfly valve, introduced to Japan 50 years to 60 years before widespread use in Japan, and in our promotion is after 70 years things. The world generally DN300 mm butterfly valve has been gradually replaced. Compared with the gate valve opening and closing time is short, the operation for the moment a small, small installation space and weight. To DN1000 example, the butterfly is about 2T, while the gate is about 3.5T, and the butterfly easily with a variety of drive combinations, with good durability and reliability. Disadvantage of rubber sealing butterfly valve used for cutting, as improper use will produce cavitation, the rubber seat falling off, damage from happening. To do this, and now has developed the international metal sealing butterfly valve, cavitation region is smaller in recent years, China has also developed a metal seal butterfly valve, in Japan in recent years has developed resistance to cavitation, low vibration, low noise, comb-shaped butterfly.  The general life of seal seat in normal circumstances, the rubber 15 years -20 years -90 years, 80 years of metal. But how to choose the right conditions, however, should requirements.  Butterfly valve opening and flow rate relationship is linear proportional change. If used to control the flow, the flow characteristics and distribution pipes are also closely related to the flow resistance, such as the installation of two pipe valve diameter, form, etc. All the same, but different loss coefficient pipe, valves, flow will be very different.  If the throttle valve in a significant reduction in the state, the valve plate on the back prone to cavitation, a damaged valve may, generally used in the 15 ° outside.  Butterfly valve in the opening, the valve body and disc shape of the front opening formed with the valve shaft as the center, completed the formation of different states on both sides, the front side of the disc moving along the direction of flow, the other side of the counter current direction of water The move, therefore, the side of the body and the formation of disc-shaped like the nozzle opening, similar to the other side of the throttle hole shaped openings, the nozzle side faster than the throttle flow rate over the side, while the throttle valve side will have the following negative pressure often there rubber seals off.  Butterfly and butterflies bar itself is not self-locking capability, in order to position the disc to install the valve stem on the worm gear reducer. With worm reducer, not only to make the disc has a self-locking capability, so the disc to stop at any position, but also to improve the operability of the valve. Butterfly operation moment, due to open and close the valve opening, and its value varies in different directions, horizontal butterfly, especially large diameter valve, due to water depth, valve axis, the water head difference between the torque generated can not be ignored. In addition, the valve device elbow import side, the formation of drift, torque will be increased. Valve opening in the middle, because the water flow torque work, operating agencies need locking. Valve structure is simple, only by a few parts, materials consumption province; small size, light weight, installation of small size, drive torque is small, simple, fast, simply rotate 90 ° to quickly open and close; and also it has good flow regulation and the closure of Seals in the large size, the use of low pressure areas, butterfly valve is the leading form. Butterfly valve is fully open position, the disc thickness is only when the medium flows through the body resistance, thus generated by the valve pressure drop is small, it has a better flow control characteristics. Butterfly valve with elastic metal seal and the seal of two seal types. Flexible sealed valves, seals can be mounted on the body or attached to the disc periphery. Metal sealed valves generally higher than the valve seal flexible, long life, but it is very difficult to completely seal. Metal seal can adapt to high temperature, flexible seal is restricted by temperature, the defects have. If asked to use as a flow control valve, the main choice is the right size and type of valve. Butterfly valve structure principle is particularly suitable for production of large diameter valves. Butterfly not only in oil, gas, chemicals, water treatment, widely used in general industry, but also for the thermal power station cooling water system. Common butterfly valve wafer type butterfly valve and flange type butterfly valve two. Wafer type butterfly valve is the valve stud connection between two pipe flanges, flange type butterfly valve is a valve with a flange with bolts on both ends of the valve in the pipe flange connection method Lan on. Strength properties of the valve is the valve the ability to withstand the pressure medium. Valve is subjected to inner pressure of mechanical products, and therefore must have sufficient strength and rigidity to ensure the long-term use without the risk of rupture or deformation. Synthetic rubber and PTFE with antiseptic application can enhance the performance butterfly valve, and meet in different working conditions. Over the last decade, the rapid development of metal sealing butterfly valve with high temperature, low temperature, resistant to corrosion, resistant to erosion, high strength alloy materials in the butterfly valve application, the metal sealing butterfly valve in the high-temperature, low temperature, strong erosion and other work conditions are widely used, and partially replaced the cut-off valves, gate valves and ball valves. Structural characteristics of butterfly valves Butterfly valve has a simple structure, small size, light weight, material consumption province, installation, small size, fast switching, 90 ° reciprocating rotation, torque and small features, for the truncated, connected, adjust the line of medium, with good flow control characteristics and close the sealing performance. Butterfly valve to transport slurry, the liquid accumulated in the pipe outlet at least. Low pressure, can achieve a good seal. Regulated performance. The streamline design of the disc, the fluid pressure drop is small, can be described as an energy-efficient products. Pole structure of the stem to pass, after quenching with good mechanical properties and corrosion resistance, scratch resistance. Valve open and close only when the valve stem rotates without lifting operation, valve stem packing is not easy damage, reliable sealing. And disc cone pin fixed, extended end to prevent out of design, in order to avoid the junction of stem and disc rupture unexpectedly collapse when the valve stem out. Connections are flanged, wafer connections, welded connections and lugs on the wafer. Drive in the form of manual, worm gear drive, electric, pneumatic, hydraulic, electro-hydraulic actuator linkage, etc., can realize remote control and automation.