The pneumatic control valve is a compressed gas as the power source, the cylinder as the actuator, and with the help of valve positioners, converters, solenoid valves, position-keeping valves, gas storage tanks, gas filters, and other accessories to drive the valve to achieve switching or proportional adjustment, to receive the control signal of the industrial automation control systems to accomplish the regulation of the pipeline medium flow, pressure, temperature, level, and other process parameters. As a result, pneumatic control valves are characterized by simple control, fast response, and intrinsic safety, without the need for additional explosion-proof measures.
Pneumatic regulating valves are usually a combination instrument formed by pneumatic actuators and regulating valves after installation and commissioning.
Pneumatic control valves are one of the industrial process control instruments widely used in petroleum, chemical, electric power, metallurgical, and other industrial enterprises.
New energy field
The world is facing the problem of an energy shortage. Coupled with China being in industrialization and urbanization, the energy demand will continue to grow, the contradiction between energy supply and demand is increasingly prominent. With the increasing tension of conventional oil and gas resources, new energy development scale is growing, it can be expected that the application of valves in the field of clean new energy will also achieve rapid growth, clean new energy demand for valves will become the new engine for the future development of the valve market.
With China’s long-term high-speed economic growth in demand for steel, iron, and steel metallurgical industry has been an important basic industry of the national economy, is to achieve industrialization support industry, is technology, capital, resources, energy-intensive industries. Energy-saving and resource conservation are significant issues that need to be addressed in the metallurgical industry today. The metallurgical industry is also facing the transformation and renewal of the original equipment, the elimination of high energy consumption, heavy environmental pollution of backward equipment, how the development of the steel industry to a higher level, energy-saving and environmental protection, and variety of structural optimization is increasing, which requires a large number of advanced equipment to do support, steel and metallurgical valves have a huge market. Energy-saving and emission reduction valve equipment have more potential market.
With the development of the times, the progress of science and technology, the people’s living standards continue to improve, the application of biochemical applications continue to be expanded and extended, followed by a large number of pharmaceutical supplies, modern, automated industrial production. Valves are necessary to control fittings in modern pharmaceutical plants fermentation workshops for cutting off or communicating fluids such as steam, water, culture medium, air, etc., regulating the flow of liquids and controlling the pressure in pipelines or containers.
Chemical fiber industry
Since the 20th century, chemical fibers have been produced with the development of polymer materials. The introduction of chemical fibers has changed the thousands of years of human history of using only natural fibers as the only raw material for textile fibers and opened up vast prospects for obtaining new, superior performance textile fibers. The raw materials for chemical fibers come from oil, natural gas, coal, agricultural and forestry by-products, etc. With the rapid growth of the oil industry, the development of synthetic fibers in terms of variety, quantity, and technological level has far surpassed the production of manufactured fibers. Chemical fiber industry in the production process, the safety and stability of the pipeline system is the key to display, and valve products need to be able to cope with the complexities of the chemical fiber pipeline system before the production process of the pipeline system to run more freely.
With the development of the pesticide and pharmaceutical industry, the requirements for cleaning, sterilization, and sealing reaction equipment in the pesticide and pharmaceutical production process have become increasingly stringent. Therefore, the valves used in the working conditions are often required to have zero leakage to avoid contamination of the drug during the production process. The entire operating space is free from irritating odors and fumes, placing strict requirements on the valve manufacturing industry. At the same time, in the pesticide industry’s development trend, all kinds of valves will be more widely used in the pesticide pharmaceutical industry.
(1) pneumatic control valve installation position, from the ground requires a certain height, valve up and down to leave a certain space, to carry out valve disassembly and repair. For regulating valves equipped with pneumatic valve positioners and handwheels, operation, observation, and adjustment must be ensured for convenience.
(2) The regulating valve should be installed on the horizontal pipeline, and up and down with the channel vertical, generally under the valve to support, to ensure that it the stable and reliable. For special occasions, the regulating valve needs to be installed horizontally on a vertical pipe, and the regulating valve should also be supported (except for small diameter regulating valves). (When installed, to avoid additional stress to the regulating valve).
(3) The operating temperature of the regulating valve should be (-30 to + 60), and the relative humidity should not be greater than 95%.
(4) The position before and after the regulating valve should have a straight pipe section. The length is not less than ten times the pipe diameter (10D) to avoid the valve’s straight pipe section being too short and affecting the flow characteristics.
(5) The diameter of the regulating valve and the process piping is not the same. They should be connected using a reducer in the small-diameter control valve installation, available threaded connection. The fluid direction arrow on the valve body should be consistent with the fluid direction.
(6) To set the bypass pipeline. The purpose is to facilitate the switch or manual operation, which can be in the case of non-stop maintenance of the regulating valve.
(7) The regulating valve should be thoroughly cleaned of foreign objects such as dirt and welding slag before installation.
(1) The valve should be stored in a dry room. Both ends of the pathway must be blocked. No stacking storage
(2) Long-term valve storage should be regularly checked to remove dirt in the moving parts, and the processing surface should be coated with anti-rust oil to prevent rusting.
(3) The valve should be installed on the horizontal pipeline, must be installed vertically. The valve stem should be upwards.
(4) Must be installed according to the direction of flow of the medium indicated by the arrow shown in the diagram.
These batch pneumatic control valve is used in steam application in power station of China.
The structure of control valve are sleeve type, packing in PTFE.