Discussion on the valve position of angle valves
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I discussed this with a ball valve manufacturer this afternoon. The manufacturer claimed that if the opening angle of the ball valve is small, it can cause the two subsequent flow processes (flash evaporation of high-temperature, high-pressure liquid) to deviate from their normal path. The pressure of the fluid in front of the ball valve is 6.0 megapascals, and the temperature is 245 degrees. There is a buffer tank below the ball valve, which is connected to a container at a pressure of 0.7 megapascals. Since the opening angle of the ball valve is small, yet the valve seat it connects to remains fixed, how can there be a deviation in the flow of the fluid? Bias flow is generally caused by differences in resistance resulting from valve seat damage and local blockages, which in turn damages the downcomer. I don’t think there is a necessary connection between the valve position and whether the fluid deviates from its path after flashing. What do you all think?
Is it like a faucet, where the shape of the water flowing out changes depending on the degree of opening?
This post was last edited by ylb913 on 2018-7-9 at 21:29. I believe what is meant by flow deviation is that when the valve has a limited flow capacity, the fluid flowing out of the valve tends to go to one side. This phenomenon is quite noticeable in gate valves; moreover, corrosive media can cause severe erosion of the valve body. We use globe valves less often, so we are not very familiar with the extent of flow deviation in them.
Typical faucets use ball valves, and there is a significant structural difference between angle valves and ball valves; ball valves can experience flow deviation, whereas angle valves have a valve seat at the bottom through which the fluid flows.
All linear stroke valves experience flow deviation; axial flow types are better.
Why do straight-stroke valves experience flow deviation?