With The Design And Realization Of The Intelligent Locator Protected By Three Off

The smart valve positioner is one of the key components for pneumatic control valves in realizing intelligent control. Along with the rapid development of modern industries of Power, Paper, Petroleum, Petrochemical, Chemical Fiber, and because of the requirements of intellectualization and networking in process control, it is imperative to develop and design smart valve positioners with independent intellectual property.During the development and design of smart valve positioners related, some critical technologies and technical processes are adopted, such as electromagnetic effect, pneumatic amplification, PID optimized control, and special process treatments, etc. Thus the control characteristics of pneumatic valves have been enhanced and these kinds of positioner are been recognized as smart.In many industry applications, the control valve need to have a special feature as Fail Freeze which means the valve would be blocked in where it was when a failure occurs. The failure could be the lost of power supply, setpoint signal and air supply.In the past, when a control valve needs to have Fail Freeze features, it may need additional parts like signal relay, solenoid valve, lock valve. All added parts will cause cost increase and stability decrease.An intelligent electro-pneumatic valve positioner based on Nozzle and damper related with this paper is one of main developing trend of valve positioners. This paper describes in detail the software and hardware designs of the intelligent valve positioner which features smart control, gives the realizing Fail Freeze feature, and proposes the software and hardware technical for low power consumption design of two-wire valve positioner. The practical application shows that the main technical performance are fairly superior to traditional valve positioners.