For wear-resistant ball valves, the valve core is made of 304 + tungsten carbide; how should the valve seat be selected?
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For wear-resistant ball valves (where the pipeline medium contains a small amount of silicon powder), the valve core is made of 304 material with tungsten carbide coating; what should be used for the valve seat? The valve seat currently in use is also 304 with tungsten carbide coating. I now want to change the material of the valve seat. I was wondering what suggestions those of you who work with valves have? Should I choose a material that is 5–10 times less hard than tungsten carbide? If so, what would that material be? Is it appropriate to replace the current 304 material of the valve stem with 17-4PH? Are there any other options? Reason? Thank you!
Also, what is the service life? It is usually in the open state, and is closed during maintenance. Does this lifespan refer to the number of years or the number of switch operations?
17-4PH is better than 304; I think 304 becomes a bit soft under high pressure, so it’s best to use 17-4PH. In most cases, however, 304 is sufficient.
I’m not sure what hardness level you require for WC; if you need a different hardness level, you could consider nickel-based alloys. It’s also fine to use 17-4PH in place of 304 at temperatures up to 350 degrees; 17-4PH has much better strength.
The hardness difference is 5-10; nickel-based alloys may not achieve this value, while spherical WC materials require a hardness of around 70-75
17-4PH is a good choice for applications in the wear-resistant industry. I’m not sure what the temperature conditions in your environment are; you might want to look into zirconia ceramic ball valves. Zirconia has a Rockwell hardness of 87, and it boasts high mechanical strengths in terms of bending resistance and compressive strength. Currently, many zirconia ceramic ball valves are in use.
I will answer your questions one by one: 1) The ball is made of 304+TCC; for the valve seat, 304+TCC is sufficient – there is no need to change the material. If a material change is necessary, factors such as corrosion resistance and deformation must be taken into account, as the deformation capacity of the valve seat directly affects the sealing performance of the valve. Additionally, for high-pressure valves, it is recommended to change the material of the ball; 17-4PH balls combined with TCC could be considered； 2) If it is TCC (tungsten carbide spraying), there is no need to consider the difference in hardness; TCC is the best choice for TCC. 3) When designing and calculating ball valves, if the strength of the 304 valve stem is sufficient, there is no need to replace it with 17-4; of course, using 17-4 would result in better strength as well as improved corrosion resistance. Everything is based on calculations.
Final selection: Both the sphere and the valve seat are made of 304 + tungsten carbide, with a hardness difference of 5. The valve stem is 17-4PH. Back to floor 6: there are currently many usable zirconia ceramic ball valves available. How effective is it?
Is the poster working on a polysilicon project? If wear resistance is the only concern, a ceramic ball valve will suffice; however, this depends on temperature, as ceramic ball valves cannot be used at high temperatures.
Back upstairs, yes. What is the temperature resistance of ceramics?
What are the operating conditions? Switch or adjust? Is it the air that carries the silicon powder, or is the liquid medium containing the silicon powder? How much pressure?