The valve is the control device of the fluid pipeline. Its basic function is to connect or block the flow of the pipeline medium, change the flow of the medium, change the movement direction of the medium, adjust the pressure and flow of the medium, and protect the normal operation of the pipeline equipment.
Many applications of industrial valves are after Watt created steam engines. In the past two to three decades, due to the needs of petroleum, chemical industry, power stations, metallurgy, ships, nuclear power, aerospace, etc., higher requirements have been placed on valves and discussions have been promoted. And the production of high-parameter valves, its working temperature ranges from ultra-low temperature -269℃ to high temperature 1200℃, and even as high as 3430℃, working pressure from ultra-vacuum 1.33x10-8Mpa (1x10-1 mmHg) to ultra-high pressure 1460MPa, and the valve diameter is from From 1mm to 600mm, and even to 9750mm, the valve materials have developed from cast iron, carbon steel to titanium and titanium alloys, high-strength corrosion-resistant steel, etc. The valve drive mode has developed from manual to electric, pneumatic, hydraulic, program control, CNC, etc. Remote control etc.
With the continuous development of modern industry, the demand for valves continues to grow, and a modern petrochemical plant needs tens of thousands of valves, and the use of valves is large. Frequent opening and closing, but often due to production, use, selection, and improper repair, the appearance of running, emitting, dripping, and leaking occurs, resulting in flames, blasting, poisoning, and scalding, which may result in poor product quality and improved energy consumption. Incidents such as equipment corrosion, material consumption improvement, environmental pollution, and even the formation of production stoppages have emerged in endlessly. Therefore, everyone expects to obtain high-quality valves. At the same time, they also request to improve the use and repair level of valves. At this time, it is for valve operators, repair personnel and engineering In addition to careful design, reasonable selection and correct operation of the valve, the technicians put forward new requests. They must also be protected and repaired in time to minimize the valve's "running, leaking, dripping, and leaking" and various incidents.
