Corrosion is the destruction and deterioration of materials under the action of various environments. The corrosion of metal is mainly caused by chemical corrosion and pitting chemical corrosion, and the corrosion of non-metallic materials is generally caused by direct chemical and physical damage. The forms of the valve's corrosion There are two forms for corrosion of metal valves, namely uniform corrosion and localized corrosion. The rate of uniform corrosion can be evaluated by the...
How to Deal with the Valve's Corrosion? Read
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4. Comprehensive treatment plans According to the above analysis of the reasons for internal leakage of valves in the thermal power plant's thermal system, combined with the differences in the purpose, structure, and operating conditions of each valve, a targeted comprehensive treatment plan is proposed for implementation. 4.1 Optimization and improvement of the valve's operation (1) The closing stroke of electric valves and pneumatic valves is preferably 0. Nowadays,...
Internal Leakages of Valves in Thermal Systems of Large-scale Thermal Power Plants (Part Two) Read
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Abstract: The valves used in the thermal system of modern large-scale thermal power plants are all high temperature and high-pressure valves. How to control internal leakages of valves has become an important content of the daily technical management of thermal power plants. The reasons for internal leakages of valves for thermal systems are analyzed and relevant solutions to internal leakage of valves of thermal systems are put forward. ...
Internal Leakages of Valves in Thermal Systems of Large-scale Thermal Power Plants (Part One) Read
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The following measures can avoid internal leakage of power plant valves: 1. Deepening understanding and holding someone responsible Establish an organization to prevent internal leakage of valves; appoint a person responsible and strictly control valve maintenance and acceptance. Preventing internal leakage of valves is by no means a task which can be done by one or two dedicated workers, and it should be taken as an important task for power companies...
Measures to Prevent Internal Leakage of Power Plant Valves Read
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The thermal loss caused by the internal valve leakage of the thermal system is an important factor that affects the thermal efficiency of the boiler. The control of the internal valve leakage is an effective way for coal-fired power plants to establish a long-term mechanism for safe production, improve the level of economic operation and establish a good social image. Attention should be paid to taking measures to prevent internal leakages of valves and mastering operation and maintenance skills....
Causes and Judgment of Internal Leakages of Power Plant Valves Read
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The sealing surface of steel valves is generally manufactured by build-up welding. The materials used for build-up welding of valves are divided into four categories according to alloy types, namely cobalt based alloys, nickel based alloys, iron based alloys and copper based alloys. These alloy materials are used to manufacture welding rods, welding wire, welding flux (including transition alloy flux) and alloy powder. Build-up welding methods such as manual arc...
Selection of Build-up Welding Materials for Valves' Sealing Surfaces Read
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A check valve is a kind of automatic valve which relies on the weight of the fluid medium or external power to open and close the opening and closing parts (disc), and it is also called a one-way valve, which is widely used in petrochemical pipeline systems to prevent the medium from flowing back, avoid the drive motor from reversing and control discharge of the medium in the container. Correct and reasonable selection and pipe installation are directly related to the safe and stable...
Selection and Installation of Common Check Valves Read
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4. Sealing elements Although the structure of the ball valve is simple, there are many factors that affect the final sealing of the ball valve due to the pressure self-sealing of media and the special structure of the ball. 4.1 Quality of sealing pairs The quality of sealing pairs of ball valves mainly manifests in the roundness of the ball and surface roughness of sealing surfaces of the ball and valve seat. The roundness of the sphere affects the...
Sealing Elements of Cryogenic Ball Valves (Part Two) Read
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1. Overview A ball valve is widely used in various working conditions due to its simple structure, small installation space and relying on medium force to seal and not being affected by external driving force. At present, cryogenic ball valves are commonly used in LNG receiving stations. The cryogenic ball valve accounts for 80% of the number of valves in the entire LNG receiving station. There is a phenomenon of internal leakages for cryogenic ball valves...
Sealing Elements of Cryogenic Ball Valves (Part One) Read
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