原文：
       30年代，美国发明了蝶阀，50年代传入日本，电磁阀到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，水力控制阀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、调节阀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，呼吸阀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，减压阀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.

“ Butterfly in the process of applying a kind of knowledge on ”是由中国蝶阀网提供的阀门新闻，译文仅供参考。另外，中国蝶阀网还提供相关产品搜索： 衬胶蝶阀 、 金属密封（硬密封）蝶阀、 通风蝶阀 、 陶瓷蝶阀 、 更多蝶阀产品、 蝶阀价格 等。

译文：
        30 years, the United States invented the butterfly valve, introduced to Japan 50 years to 60 years before widespread use in Japan, while in China it is 70 years to promote things after. 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 Bellows Seal Valvessmall, small installation space and weight. To DN1000 example, the butterfly is about 2T, while the gate is about 3.5T, and butterfly easy to drive with a variety of combinations, with good durability and reliability.  Disadvantage of rubber sealing butterfly valve used for cutting, because 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.  General sealing seat under normal Check Valves conditions the life of the rubber for 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 Plug Valves 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 frontButterfly Valves 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 of the cutting side of the flow rate faster than many and expenditure side will have the following negative pressure valve often there rubber seals off.  Butterfly valve operation torque,Safety Valves 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 shaft, the water generated by the first bad moment 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, organizations need to self-locking operation.

原文来源：http://www.1diefa.com/

2010-07-14 06:28

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