Pneumatic valve used in five major problems

a, why watt, pneumatic valve, small open work easy oscillation
for single core, when the medium is away, watt, pneumatic valve, good stability; When the medium is flow closed type, watt, poor stability of pneumatic valve. Two-seater pneumatic valve has two pneumatic valve core, the pneumatic valve core in the flow close, pneumatic valve core in the flow, in this way, when you are working in a small open degree, the flow of the closed type pneumatic valve core is easy to cause the vibration of watt, pneumatic valve, this is the watt, pneumatic valves cannot be used for small open degree work.
2, why can't a double seal pneumatic valve used as cut off the pneumatic valve
two-seater pneumatic valve pneumatic valve core has the advantage of force balance structure, allow the pressure difference is big, but its disadvantage is that the two seal face not good contact at the same time, cause leakage. If it is used to cut off at artificially, mandatory, obviously the result is bad, even as it made many improvements ( Such as double seal sleeve pneumatic valve) It is not desirable.
3, pneumatic valve stem what straight stroke control performance is poor, held in quarter-turn pneumatic valve performance is good
straight travel pneumatic valve pneumatic throttle valve core is vertical, and medium level, pneumatic valve cavity flow is bound to turn down turn, make pneumatic valve flow becomes quite complex ( Shapes such as 'S' type) 。 In this way, there is a lot of dead zone, provide the space for medium of precipitation, in the long term, causing congestion. Quarter-turn pneumatic valve throttle direction is horizontal, flow into the medium level, level, easy to take unclean medium, flow simple at the same time, the precipitation of medium space is very few, so held in quarter-turn pneumatic valve performance is good.
4, why the straight stroke regulating pneumatic valve pneumatic valve stem is fine
it involves a simple mechanical principle: large sliding friction and rolling friction is small. Straight travel pneumatic valve pneumatic valve rod moves up and down, packing a little pressure, it will be tightly wrapped pneumatic valve stem, produce bigger return difference. Therefore, pneumatic valve stem design very tiny, packing and commonly used small friction coefficient of ptfe packing, in order to reduce the return difference, but the problem is sent pneumatic valve stem thin, easy to bend, packing and short service life. Travel the best way to solve this problem, is to use pneumatic valve pneumatic valve stem, namely quarter-turn class regulating pneumatic valve, its pneumatic valve stem ~ times thicker than straight travel pneumatic valve stem, and select long-life graphite packing, pneumatic valve stem good stiffness, packing long life, instead of the friction torque is small, poor little back.
5, why quarter-turn pneumatic valve to cut off the pressure difference is bigger?
quarter-turn kind of pneumatic valve to cut off the pressure difference is bigger, because the medium on the pneumatic valve core or pneumatic valve plate of resultant force on the rotating shaft torque is very small, so it can bear large pressure difference.