Pneumatic regulating stainless steel butterfly valve

Pneumatic regulating stainless steel butterfly valve

Industrial process control continues to network, distribution of intelligent development, adapted to the requirements of the digitalization of equipment management, regulating valve is an important executive component of the process control system, control regulating valve operation of the distribution of intelligent solutions came into being. Intelligent valve positioner has the functions of data processing, state identification, fault diagnosis, online and offline testing, two-way communication and so on. The process control system controls the regulating valves through the field bus, which enables the manager to realize the predictive maintenance and scientific management of the regulating valves. The development of computer technology, electronic technology, communication technology, intelligent predictive diagnostic technology, the requirements of intelligent valve positioner must adapt to the network communication and power supply common line, its core part of the pneumatic control components must realize ultra-low energy consumption operation, to ensure that the network bus control system operation is safe and reliable.

Traditional pneumatic valves use a large number of electromagnetic principle as electrical energy - mechanical energy conversion level, the application of coil and solenoid electromagnetic force effect will control the electrical signal conversion bit mechanical action to promote the spool of the valve action, so as to realize the switching of the gas path or gas pressure, flow control. Although the solenoid and coil has the advantages of low price and convenient processing, but its power loss, slow response speed, heat, mechanical wear, electromagnetic interference and other shortcomings exist at the same time, by changing the solenoid material and valve processing to avoid the above problems at the same time, resulting in a substantial increase in cost and processing technology is becoming increasingly complex, and can not solve the problem at the root. The realization of low power consumption, intelligent integration, high precision, fast response and long life of the pneumatic control has become an urgent need.

First, the definition of intelligent valve positioner

According to the national standard GB/T22137.2-2008 “industrial process control system with valve positioner Part 2: pneumatic output intelligent valve positioner performance evaluation method”, intelligent valve positioner

(IntelligentValvePositioner) is an intelligent process control instrument based on microprocessor technology and adopts digital technology for data processing, decision generation and two-way communication. Intelligent valve positioner according to the power supply can be divided into separate power supply and do not need separate power supply; according to the explosion-proof level can be divided into explosion-proof and non-explosion-proof.

Second, the traditional valve positioner problems

2.1 The use of nozzle baffle technology, that is, the mechanical force balance principle of operation, more movable parts, vulnerable to temperature, vibration;

2.2 Because of the regulating valve specifications, packing friction situation is different, regulating valve hardware combination is difficult to achieve the best control state;

2.3 The flow of the signal is unidirectional to the control instrument into the positioner, when there is a failure, can not self-diagnose the fault location or cause;

2.4 The nozzle holes are easily blocked by dust in the air supply, so that the positioner can not work properly;

2.5 The nozzle needs to be continuously supplied with compressed air, which consumes more energy;

2.6 Travel and zero point adjustment, need to be repeatedly adjusted, tuning trouble;

2.7 Single function, poor expandability.

Third, the advantages of intelligent valve positioner

3.1 High positioning accuracy and reliability. Less mechanical moving parts, the input signal and the valve position feedback signal direct digital comparison, not easily affected by the environment, good stability, there is no mechanical error caused by the impact of the dead zone, has a higher positioning accuracy and reliability;

3.2 Convenient modification of flow characteristics. Intelligent valve positioning includes linear, equal percentage, fast open characteristic function module, which can be set through the button or the upper computer, handheld setter for data setting;

3.3 Zero point and range adjustment is simple. Zero point adjustment and range adjustment do not interfere with each other, the adjustment process is simple and fast;

3.4 Diagnostic and detection functions. In addition to the general diagnostic function, it can output the feedback signal corresponding to the actual action of the regulating valve, which can be used to monitor the working status of the regulating valve from a distance. Intelligent valve positioner receiving digital signals, with two-way communication capabilities, can be used locally or remotely using the host computer or handheld operator for valve positioner configuration, debugging and diagnosis.

Translated with DeepL.com (free version)