November 18, 2024
Angle stroke class pneumatic control valve, the angle stroke actuator structure of many types, making it complicated, should first consider the structure of simple, free movement, small size, large thrust actuator, the typical structure is a double-piston rack and pinion rotation type. It is worth emphasizing that the traditional “straight stroke piston actuator + angle iron crank linkage” should be eliminated.
Bellows-sealed sleeve pneumatic control valve, bellows-sealed sleeve pneumatic control valve, the use of sleeve-guided, pressure-balanced spool, suitable for large differential pressure occasions. The use of balanced sealing ring instead of the upper seat, so that the traditional sleeve double-seat valve structure into a sleeve single-seat structure, this improvement ** improve the leakage level of sleeve control valve. The bonnet adopts double sealing of bellows and packing, which fundamentally eliminates the possibility of media leakage. This type of regulating valve is suitable for flow pressure control of toxic or precious media. Valve spool using pressure balanced structure, opening and closing force is small through the smaller actuator thrust can control the high pressure difference of the working conditions. Good sealing performance, large allowable differential pressure.
Pneumatic control valve mode of action: air-open type (normally closed) is when the diaphragm head air pressure increases, the valve to increase the opening direction of action, when the input air pressure reaches the upper limit, the valve is in a fully open state. Conversely, when the air pressure decreases, the valve acts in the direction of closing, and when there is no input air, the valve is fully closed. Gu usually we call the air-open type regulating valve as the fault closure type valve.
NORGREN solenoid valve main accessories, and pneumatic control valve supporting the use, it accepts the regulator's output signal, and then its output signal to control the pneumatic control valve, when the regulator valve action, the valve stem displacement and through the mechanical device feedback to the valve positioner, the valve position status through the electrical signal to the upper system. Valve positioner according to its structural form and working principle can be divided into pneumatic valve positioner, electric - gas valve positioner and intelligent valve positioner.
Electric valve equipment is to keep the gate valve program control, automation control and remote control essential driver machine equipment, its movement of the whole process can be manipulated by the travel arrangement, turn distance or radial thrust size. Electric ball valve production application scenarios electric valve and pneumatic adjustment valve application convenience and adjustment precision and other advantages, many have long replaced the application of manual adjustment valves. In the application of electric valve pneumatic adjustment valve, electric valve application regulations must have a switching power supply, pneumatic adjustment valve application must have a source.
Pneumatic control valve is a very wide range of knowledge, and in the regulation system is a pneumatic control valve is essential, it is composed of an important part of the industrial automation system, you want to understand the valves on your equipment should be the first to understand the principle of pneumatic control valve work.
Solution: Replace the conventional screw type; it is recommended that the connected line be changed to a thin line. Pneumatic control valve maintenance and failure analysis of pneumatic control valve working performance will directly affect the quality of the work of the entire regulatory system. As the pneumatic control valve in the field is in direct contact with the regulated medium working environment is very harsh, so it is easy to produce a variety of faults. In the production process, in addition to eliminating these faults at any time, but also must carry out regular maintenance and regular maintenance. Especially for the use of particularly harsh environment of the control valve, should pay more attention to maintenance and regular maintenance.
Pneumatic control valves have two types of mode of action, gas open, gas shut-off, gas open valve with the increase in signal pressure and openness increases, no pressure signal, the valve is in a fully open state, gas shut-off is the opposite. Reasonable choice of regulating valve mode of action, to ensure production safety, improve product quality and reduce economic losses is essential. Can also be through the gas on, gas off the correct choice of mode, to achieve the role of fault retention.
Pneumatic control valve used for a period of time will often appear this fault, first of all, the valve stroke adjustment. Failure to meet the requirements, usually the actuator or accessory leakage, the rigidity of the actuator spring fails to meet the requirements, push rod or stem bending, deformation, spool damage or spool, debris in the valve seat, the media flow direction is not correct, packing friction is too large and so on within the original cause. Damaged springs, push rods, valve stems, valve spool, valve seat should be replaced.
Chemical automation in the valve has also been the implementation of agile, can be completed on the flow, pressure, level and temperature of the accurate control, in the chemical automatic control system, control valve belongs to a major actuator, its type and device quality on the conditioning circuit of the conditioning quality, in the development of the degree of industrial automation, pneumatic control valves as a kind of outstanding actuator has also been widely used.
