Valve selection in low-temperature environments
Thread Content
Dear experts: I have a small project in which the operating temperature can drop to -40°. The client requires that stainless steel be used for the pipes and fittings. I would like to ask you how to select valves for such low-temperature conditions. The medium involved is natural gas and compressed air at a pressure of 3 kg; the pipe diameter is DN20. Are materials such as Z61H-16P, J61H-25P, and Q61H-16P suitable for this purpose?
The temperature you have is okay; it’s not low. Any stainless steel valve will do. We have ones at over -190°
Those who know about it can share their thoughts freely~ Thank you! :)
Stainless steel will work; 304 stainless steel is sufficient, as the temperature isn’t that low
Uh, is this the ambient temperature? -An environmental temperature of 40°C is not very low for valves either; the media flowing through them are natural gas and compressed air, so a 304 material is sufficient – there’s nothing special about it. It’s just that the environmental temperature is a bit low. Think about the lowest temperatures in some areas of China during winter; they’re roughly the same as this temperature. Are there any special requirements for ordinary valves used in those places? The environmental temperature isn’t an issue, but the temperature of the medium does need to be taken into consideration. What about liquid nitrogen at -196°C? In such cases, it’s necessary to use longer rods to prevent workers from getting frostbite when operating the valves, or to ensure that the actuators can withstand such low temperatures. The environmental conditions in this case aren’t a problem
For low-temperature valves, it is important to ensure that a sealed valve chamber does not form; for example, in some double-sealed ball valves, a pressure relief mechanism for the valve chamber is necessary. Generally, low-temperature valves operating at temperatures above -50°C do not require an extended valve stem, but it can be added if the user has special requirements. Since the medium used by the poster contains flammable and explosive gases, non-metallic sealing valves must have fire and static electricity protection features. It’s not enough for the poster to just write down the generic model numbers; a more detailed table of valve parameters is needed.