Causes of cavitation damage to valve stems
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Under normal circumstances, the pressure is lowest at the valve where throttling occurs; it is at the valve head that bubbles are formed. In practice, it is usually the valve head that suffers from cavitation damage. In my opinion, the place where the bubbles burst should be a certain distance behind the valve, and the bursting of these bubbles can cause vibrations in the pipeline as well as unusual noises. I would like to ask my fellow sailors: what is the reason for the damage to the valve head?
Now that we know what causes cavitation, the focus should be on finding ways to reduce its occurrence; it’s pointless to keep worrying about it. By the way, it would be more accurate to say where exactly this phenomenon occurs, that is, in which area. This is the result of the characteristics of cavitation; such corrosion spots generally appear on the surface of the impeller cover. For reference.
This isn’t cavitation in a centrifugal pump either
I’m sorry the title misled everyone; it’s the valve that’s to blame, the corner valve
Many pipe fittings experience throttling, and the areas with the highest flow velocity are where cavitation is most likely to occur
This post was last edited by HEJIYUER on 2020-8-29 at 21:42. The area with the highest flow rate is not the location where cavitation damage occurs. Cavitation: It occurs when gas turns back into liquid. The degree of cavitation can be mild or severe; the more severe it is, the further downstream the bubble rupture point occurs. When the bubble encounters a resistive element, it bursts and releases energy (kinetic energy is converted into static pressure). Seat valves can \"hold\" cavitation within the valve body (causing damage to the valve), but rotary valves (such as butterfly valves) cannot hold it in place; as a result, the cavitation point moves downward, causing damage to downstream equipment. Therefore, butterfly valves are rarely used in situations involving severe cavitation. For valves operating under cavitation conditions, other valves downstream should not be installed nearby, and bends should be minimized as much as possible.
I’m also a bit confused about this. The damage to the valves is supposed to be caused by erosion rather than cavitation; online searches also mention that cavitation leads to damage at the valves. I’m not entirely sure about this, and I hope fellow sailors can help me out