Import regulating pneumatic valve in use in the process of knowledge in this paper

import regulating pneumatic valve ( English: butterfly valve is closed ( Pneumatic disc or disc to disc, revolve around pneumatic valve shaft to a pneumatic valve open and close, mainly in the line cut off and throttling. Imported pneumatic adjustment valve opening and closing is a disc-shaped butterfly plate, the pneumatic valve body around its own axis of rotation, so as to achieve the aim of opening and closing or adjust. Regulate imported pneumatic valve fully open to the barrier is usually less than °, imported pneumatic valve and butterfly pole itself has no self-locking ability, in order to butterfly plate positioning, in the pneumatic valve stem with worm gear reducer. The use of worm gear reducer, can not only make the butterfly plate with self-locking ability, make the butterfly plate to stop at any position, can also improve the aerodynamic performance of the valve. Industrial specialized characteristics of imported pneumatic valve adjustment ability of high temperature and pressure scope is higher also, pneumatic valve nominal diameter, pneumatic valve body is made of carbon steel, pneumatic valve plate seal using metal ring instead of rubber ring. Large high temperature regulating pneumatic valve USES the steel plate welding manufacturing, mainly used for the duct smoke and gas of high temperature medium.
in DN, for example, the import about T adjust the pneumatic valve, pneumatic valve about brake. T, and import to adjust pneumatic valve and all kinds of driving gear combination, good durability and reliability. Rubber seal butterfly pneumatic valve fault is for the use of throttle, due to the improper use will produce cavitation, make rubber peeling, damage, etc. For this, now again on the international development of metal seal import pneumatic valve adjustment, reduce cavitation area, in recent years, our country is also developing a metal seal imported pneumatic valve adjustment, in Japan in recent years also developed cavitation resistance, low vibration, low noise of the comb toothed imported pneumatic valve adjustment. Under normal circumstances, the life of a general seal seat - rubber Years and years - metal Years. But how to correctly choose should according to the working condition requirements.
import to adjust the opening of pneumatic valve and flow, the relationship between the linear basically percentage changes. If is used to control the flow, the flow characteristic and pipe flow resistance have close relationship, such as two pneumatic valve diameter pipe installation, forms, etc. All the same, and the pipe loss coefficient, pneumatic valve flow will be a big difference. 
如果气动阀门处于节流幅度较大状态，气动阀板的背面容易发生气蚀，有损坏气动阀门的可能，一般均在°外使用。 
进口调节气动阀处于中开度时，气动阀体与蝶板前端形成的开口形状以气动阀轴为中心，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，一侧气动阀体与气动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，而节流侧气动阀门下面会产生负压，往往会出现橡胶密封件脱落。 Import regulating pneumatic valve, operating torque for the opening and the direction of pneumatic valve opening and closing its different values, different horizontal imported pneumatic valve adjustment, especially large diameter pneumatic valve, due to water depth, pneumatic valve shaft, the water head difference generated by the torque also nots allow to ignore. In addition, pneumatic valve inlet side bend, form the bias current, torque will be increased. Of the opening of the pneumatic valve in the middle, because the water flow torque, operators need to be self-locked.