What are the temperature resistance values for valve materials CF8, CF8M, CF3, and CF3M?
Thread Content
Hello everyone, I’m a newcomer to the valve industry. I would like to ask: what are the operating temperature ranges for valves made of materials such as CF8, CF8M, CF3, and CF3M? How should I enter the minimum to maximum temperature values on the sign? I would appreciate it if everyone could share their opinions
Ultra-low temperature valves, resistant to -254°C (liquid hydrogen) to -101°C (ethylene)
Depending on the operating conditions, if no such requirements exist, we generally set it between -29 and 300 degrees Celsius. . Of course, it also depends on whether there are other materials inside the valve, such as rubber, PTFE, and so on. In short, use the one with the lower temperature. .
It has a hard seal, but when I looked up information on 304 and 316 materials, I saw that the operating temperature range is from -268 to 649°C. So can they really withstand low temperatures as well as high temperatures?
Both the lower limit of -268 and the upper limit of 649 require processing in order to reach those temperatures; generally, since customers don’t request this, no such processing is carried out. So there’s no need to set it that high. . .
Can 304 withstand -100 degrees? To achieve this, what kind of procedures are required? Please advise
It’s possible. Cryogenic treatment, also known as low-temperature treatment, involves placing the valve in liquid nitrogen for a certain period of time. After removing it, if there is a leak, it needs to be repaired; if there is no leak, then it can be used
The valve materials CF8, CF8M, CF3, and CF3M are all austenitic stainless steel castings, suitable for use in corrosive media at working temperatures ranging from -196°C to 600°C.
When indicating temperature on valve labels, it is not done based on the temperature of the material: 1: It should be indicated according to the design temperature – use the temperature specified in the design specifications, or follow the manufacturer’s standards. If you base it on the material’s temperature, you will be at a disadvantage. 2: For austenitic stainless steels such as CF8, CF8M, CF3, and CF3M, there is a pressure-related curve for their temperatures; under normal temperature and pressure conditions, heat treatment can raise their temperature to 649°C (theoretical value). However, when under pressure, the temperature of the valve components decreases! One can refer to valve design manuals or relevant technical books. 3: These valves can be used in low-temperature or cryogenic applications, but those that have been exposed to low-temperature shock are classified into two types depending on the design standards: -46°C and -110°C; the cooling method involves alcohol plus liquid nitrogen (with adjustable proportions). 4: Placing the valve in liquid nitrogen is a method for ultra-low-temperature testing, and generally, materials need to undergo corresponding cryogenic treatment and cold-shock treatment during processing! Check the deformation amount of the material! It means that the valve’s sealing performance meets the requirements at normal temperatures, and it also meets those requirements at extremely low temperatures! Two tests need to be done! 5: Corrosion resistance is relative; in many harsh environments, even austenitic stainless steels are not suitable. It is necessary to select the appropriate type and material based on specific conditions