Advanced modern industry is marked by production automation. From the development history and progress of automation systems, changes in technical tools play a very important role. Various advanced control methods continue to appear, but the basic control law has not changed, and the improvement of technical tools is changing with each passing day. The development and use of smart meters is a bright future for industrial automation. A typical automation control system has three main parts: detection, control, and execution. In recent years, changes in the detection and control instruments under the influence of digital technology and microprocessor technology are obvious to all, and the link of the actuator, especially the regulating valve as the main product, has also made great progress. The traditionally used regulating valve basically meets the needs of many industrial systems, but with the large-scale development of modern industry.

How to produce more and better advanced products, how to improve product quality standards, how to operate more effectively and safely, how to make full use of resources, save energy and protect the ecological environment, people have higher requirements on regulating valves These requirements can be summarized as follows: more stable quality, more reliable work, and safer operation. In the process control, if the direct contact of the regulating valve with the fluid fails, the consequences are unimaginable.
 
In the petroleum industry, from oil fields to refineries, various production units are centrally monitored and controlled on a large scale. Most of the operating conditions are performed at high and low pressures or temperatures, and the medium is a variety of flammable and explosive oils. A variety of oil products, therefore, the reliability and fire resistance of the control valve are put first. In the chemical industry, the diversity of processes and changes in process conditions, the control and implementation of the four major thermal variables of temperature, pressure, flow rate and liquid level, have special problems that require regulating valves to be applicable.
 
In the power industry, it is very important for a thermal power plant to control the boiler. It is important to maintain the water level in the boiler regulation system to avoid the accidental opening and closing of the regulating valve. To ensure the working performance and reliability of the regulating valve, the following requirements are fulfilled:
 
1. Guarantee the quality of the regulating valve The selection of the regulating valve must be strictly calculated; the type, caliber and various performances must meet the requirements; the materials of the various parts of the regulating valve must be strictly selected, and they must have sufficient strength and rigidity, according to The standard has passed pressure test and air tightness test. The manufacturer''s manufacturing technology and test methods are in compliance with the standards and must be signed and approved by the competent authority. It is strictly forbidden for small factories without production conditions to carry out production.
 
2. Ensuring reliable operability. This does not refer to the manufacturing quality of the regulating valve itself, but also includes the training and improvement of the quality of the operator. In order to prevent misoperation, the craftsman 1 must pay attention to the precautions indicated on the nameplate. According to China''s new pneumatic control valve standard (GB / T4213-92), the nameplate of the pneumatic actuator must indicate at least the name of the manufacturer, product model, rated flow coefficient, design bit number, product number, and year and month of manufacture. The valve body should be cast or punched to indicate the direction of flow of the medium and the DN value and the word and value of PN. Important valves must have sufficient accessories, such as positioners, limit switches, etc. There should be enough installation space and operation space, sufficient installation space and operation, sufficient lighting, and strict operating procedures.

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