Pneumatic valve adjustment in the process of applying knowledge 2)

s, the United States invented the pneumatic valve, butterfly from Japan to years in Japan are widely used, but in China this year is to promote. General pneumatic valve DN mm butterfly world has gradually replaced. Pneumatic valve and gate opening and closing time is shorter, operation torque, small space for installation, light weight. As the DN, for example, about T butterflies, and about. Tons of door is pneumatic butterfly valve and drive various combinations with good durability and reliability, easy.
rubber seal butterfly pneumatic valve faults are throttling, due to the improper use will produce cavitation occurs, rubber peeling, damage. In order to achieve this goal, it has developed international metal sealing butterfly pneumatic valve, in recent years, reduce the cavitation area, China also developed in Japan pneumatic valve, metal hard seal plate developed cavitation erosion resistance, in recent years, low vibration, low noise comb of the butterfly.
general sealing seat under normal circumstances, the life of a year - Years of rubber, metal, year - Years. But how to choose the right will be according to the working conditions.
the ratio between the pneumatic valve open and flow adjustment relations change basically is linear. If is used to control the flow, pipe flow characteristics of flow resistance is also closely related to the two pipes, the installation of the pneumatic valve, such as the diameter, shape, etc. All the same, and the pipe loss coefficient of different flow control pneumatic valve will have the very big difference.
if pneumatic valve, by throttling in countries prone to cavitation pneumatic valve plate on the back, have damaged the possibility of a pneumatic valve outside ° commonly use.
butterfly at the opening ceremony, the body and disc in front of the pneumatic valve shaft as the center to form the shape of the mouth, different countries to complete the formation of both sides, along the flow direction, on the other side of the mobile plate of the movement of the positive water flow direction, therefore, on one side of your body open with pneumatic valve plate shape such as nozzle, a similar hole shape the other side of the mouth, the side of the mouth flow than cut surface formation, cut surface will produce the following negative pressure pneumatic valve rubber seal close often arise.
pneumatic valve operating torque, because open and close the pneumatic valve opening, its value is in different directions, the level of butterflies, pneumatic valve, especially large-diameter gate into the water head difference in torque, because the water depth, pneumatic valve spindle, can produce different nots allow to ignore. In addition, the elbow the pneumatic valve inlet equipment currently form of prejudice, the torque will be increased. When the pneumatic valve opening in the middle, at work, water flow, operators need to be self-locked.