Valves are widely used in various fields of national economy and people's livelihood. Because they have to adapt to the requirements of various working conditions, their varieties are huge. my country's electric actuator manufacturing industry is very large, with thousands of valve manufacturers all over the country. At present, my country has become one of the countries with the largest valve output and market demand in the world. However, most of the valve industry in my country is small and medium-sized enterprises. The good and the bad are mixed. There are less than 10 companies with an annual output value of more than 100 million yuan. Even compared with other domestic machinery industries, there is a big gap in equipment and technical level, and they are truly independent. There are few units with the ability to research and develop high-end products. Therefore, in large-scale petrochemical, nuclear power, oil and gas long-distance pipelines and other major engineering projects, the supporting valves are currently mainly imported.
The broadest definition of an actuator is: a drive device that can provide linear or rotary motion, which uses a certain driving energy and works under a certain control signal. The actuator uses liquid, gas, electricity or other energy sources and converts it into a driving function through motors, cylinders or other devices.
The basic types of valve electric devices have three drive modes: Part-Turn, Multi-Turn and Linear.
Valve electric devices can be divided into two categories: linear travel and angular travel. It is an indispensable and important equipment in an automatic control system. Its main task is to proportionally convert the control signal sent by the regulator into a linear displacement or an angular displacement. Drive the valve, baffle and other adjustment mechanisms to achieve automatic control. Therefore, it is widely used in the automatic control field of power, metallurgy, petroleum, chemical and other industrial sectors.
In the past 10 years, due to the widespread adoption and absorption of new technologies, new achievements and mature experience in microcomputer control, micromechanics, etc., valve electric devices have developed rapidly, and microcomputer-based valves with the "microcomputer + follow-up system" structure mode have been widely used. In the electric device, the microprocessor completes signal transmission, adjustment parameter switching, status indication, and control output to improve flexibility in adjustment performance, use, and maintenance.
The reliability of a valve electric device refers to its ability to complete a specified function under specified conditions and within a specified time.
"Required conditions" can generally be summarized as:
(1) Environmental conditions: refers to the environmental characteristics that can affect the performance of the valve electric device, such as temperature, humidity, air pressure, magnetic field, mechanical shock, vibration, dust, etc.
(2) Power condition: refers to the power characteristics that can affect the performance of the valve electric device.
(3) Load condition: refers to the load characteristics that can affect the performance of the valve electric device, such as torque, the type and characteristics of the controlled object, etc.
(4) Use and maintenance conditions: The reliability of valve electric devices can only be achieved in use and improved in maintenance. For use and maintenance conditions, the first thing to pay attention to is perfect use and maintenance; secondly, The operator must be required to reach the corresponding technical level.
