Carbon steel valves in Baidu LibraryThe temperature can reach 425 degrees, is not without welding carbide seal, who has no detailed material ah?,
The 425 degree here means that WCB carbon steel can withstand such high temperatures and has little to do with sealing. In the sealing surface location, surfacing, etc., is the role of erosion resistance. If your body can only withstand 200 degrees, but your valve that can withstand 1000 degrees, which makes sense? So resistance to temperature is a comprehensive concept, and the temperature depends on the lowest temperature resistance in all of your parts (somewhat similar to the cask theory in economics). Of course, scouring will be a little faster at high temperatures.
This 425 DEG C is the limit temperature of ASTM A216: -30 DEG C - +425 DEG CBut if the sealing surface of rice now is PTFE, it can be as high as +80 degrees centigrade. If the PTFE material is good, it can reach +150 centigradeTherefore, the body material is carbon steel, only that the valve body of the temperature range of this materialLook at the inside of the valve,For example, cryogenic carbon steel in LCB, ASTM, A325 can reach -46 degrees --+340 degrees centigradeHowever, if the sealing surface of your body is the sealing surface of plain carbon steel, the temperature range of this carbon steel valve is only the temperature range of the ordinary carbon steelIf you say that now is the carbon steel valves used in the sealing surface of the safety valve, you must need welding hard alloy (STL or D series, etc.) should have strong hardness of hard alloy after treatment, impact resistance.Depends on your flow channel medium, if it is high temperature, it is best to use 316, and so onThe use of valves is a combination of considerations
What valve do you have to see and hardening?. Usually only about 300 degrees. Special hardening can only be done at 425 degrees
I don't know what you said is the Stellite hard alloy of? That's what we call cobalt base. On the seal, welding cobalt base is not in order to meet his temperature, but also to meet the wear resistance, corrosion resistance. The general condition is both wear resistant or wear resistant and corrosion resistant performance, some conditions may also require high temperature wear resistance and corrosion resistance, it will be based on the condition to decide whether the welding in the manufacturing process of the valve!
