Adjustment of the pneumatic valve knowledge is discussed
by:AIRWOLF2021-01-15
s, the United States invented the pneumatic valve, butterfly s introduced to Japan, to s widely used in Japan, and popularized in our country is s.
The world in general DN millimeter above pneumatic valve has gradually replaced the brake pneumatic butterfly valve.
Compared with the control pneumatic pneumatic valve and gate valve opening and closing time is short, small operation torque, small installation space and light weight.
DN, for example, about T butterfly pneumatic valve, pneumatic valve about brake.
T, and the adjustment of pneumatic valve is easily combined with various drive, 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 international development metal sealing butterfly pneumatic valve, cavitation zone decreases, and in recent years, our country is also developing a metal seal butterfly pneumatic valve, in Japan in recent years also developed cavitation resistance, low vibration, low noise of the comb tooth profile control pneumatic valve.
general sealing seat under normal circumstances, the life of a rubber -
Years and years - metal
Years.
But how to correctly choose should according to the working condition requirements.
butterfly pneumatic valve opening and the flow rate, 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.
if throttled the larger state of pneumatic valve, pneumatic valve plate on the back of the easy cavitation occurs, the possibility of damage pneumatic valve, are generally used on outside °.
butterfly pneumatic valve opening is in, the pneumatic valve body and disc front of mouth shape with pneumatic valve shaft as the center, on both sides of the form a complete different state, the butterfly plate on one side of the front end of downstream water direction, the other side of the upstream water direction, therefore, on one side of the pneumatic valve and pneumatic valve plate form like opening nozzle shape, on the other side is similar to throttle aperture openings, nozzle side of more quickly than the throttling velocities, and side below will produce negative pressure pneumatic valve, throttle rubber seals often can appear fall off.
butterfly pneumatic valve, operating torque for the opening and the direction of pneumatic valve opening and closing its different values, different horizontal 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.