With the development of China's science and technology, automatic valves produced by China's chemical industry have been rapidly implemented, which can complete the accurate control of flow, pressure, liquid level and temperature. In the chemical automatic control system, the control valve is a main actuator, and its model and device quality have a major impact on the conditioning quality of the c···

Valve is the accessory of equipment and pipeline, its maintenance should be combined with the maintenance of equipment and pipeline.   According to the regulations for maintenance and repair of refinery equipment stipulated by the Ministry of chemical industry of raw materials and fuels, the repair contents of high, medium and low pressure valves for oil products, steam, water and ···

Pressure maintenance valve is a complex, dangerous and technical work. Besides being bold and prudent, pressure maintaining valve should also have strict scientific attitude. Especially, it is necessary to conduct leakage blocking work of explosive, highly toxic, high temperature, high pressure and radioactive media, and strictly follow the pre determined scheme and relevant safety regulati···

The connection parts such as nut, spring washer, stop washer, cotter pin are commonly used to prevent the nut from loosening. The connection structure of stem and closure part is usually used the method of stopping washer and flange washer to prevent looseness, and the effect is better.   In addition, the methods used to prevent the valve from loosening include the fixing method of···