The valve is the control component in the pipeline fluid delivery system. It is used to change the cross-section of the passage and the flow direction of the medium. The valve has the functions of diversion, cut-off, throttling, checkback, shunt or overflow pressure relief. Sealing surface damage due to human damage and natural damage of two. Man-made damage is due to poor design, manufacturing is not refined, improper material selection, improper installation, poor use and maintenance and other factors caused. Natural damage is the valve under normal wear and tear, is the media on the sealing surface of the inevitable corrosion and erosion caused damage. Specifically, the valve sealing surface damage caused by the following main reasons: 1. Improper installation and poor maintenance lead to sealing surface is not working properly, the valve is sick, prematurely damaged the sealing surface. 2. Improper selection and damage caused by poor handling. Mainly in the absence of conditions based on the conditions selected valve, the cut-off valve when used as a throttle valve, resulting in the closure of the pressure is too large and closed too fast or lax closed, so that the sealing surface erosion and wear. 3 sealing surface processing quality is not good, mainly in the sealing surface cracks, pores and ballast and other defects, is due to improper selection of welding and heat treatment and surfacing and heat treatment caused by poor handling, sealing surface hard to ferry Too high or too low, because of the wrong choice of materials or improper heat treatment caused by uneven sealing surface hardness, erosion resistance, mainly because the bottom of the metal in the surfacing process is blown to the above, diluting the sealing surface alloy composition Caused by. Of course, there are also design issues. 4. Mechanical damage, sealing surface in the process of opening and closing will have scratches, bumps, crushing and other damage. Between the two sealing surfaces, under the action of high temperature and high pressure, atoms seep into each other to cause adhesion. When the two sealing surface to move each other, the adhesion Department easily pull tear. The higher the sealing surface roughness, the more likely this phenomenon. During the closing process of the valve, the valve flap will bruise and crush the sealing surface during the process of returning to the seat, so that the sealing surface is partially worn or impressed. 5 medium erosion, it is the media activities on the sealing surface wear, flushing, cavitation results. Media at a certain speed, the media in the fine particles of the conflict against the sealing surface, causing local damage, high-speed activities of the media directly rinse the sealing surface, causing local damage, the media mixed flow and partial evaporation, the anger gas explosion Impact sealing surface, causing partial damage. Erosion of the media combined with chemical erosion alternating role, will be a strong erosion of the sealing surface. 6. Electrochemical erosion, the sealing surface contact with each other, the sealing surface and the closure body and valve body contact and the concentration of the media, oxygen concentration and other reasons, will have a potential difference electrochemical corrosion occurs, resulting in the anode side of the sealing surface is erosion. 7. Chemical erosion of the medium, near the sealing surface of the medium in the absence of current circumstances, the media directly from the sealing surface and chemical effects, erosion sealing surface. Carbon Steel Tube Mill,Tube Mill Machine,Welded Tube Mill,Tube Mill Yangzhou Donglun Industrial Equipment Co., Ltd , https://www.dltubemill.com
How to avoid the valve sealing surface damage?
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