Regarding the material of the three-valve assembly
Thread Content
For measuring the flow rate of high-temperature fluids, when the fluid temperature is below 700 degrees, differential pressure transmitters are used; obviously, the location of these transmitters is not exposed to high temperatures. But does the three-valve assembly used in such instruments still need to be designed for high-temperature conditions? Are there any three-valve assemblies that can withstand such temperatures?
Well, it depends on where your three-valve assembly is installed You need to judge such issues based on the specific circumstances on site.
The location of the three-valve assembly on-site is definitely at low temperature, with a slight amount of nitrogen being blown back as well. Currently, the parts that are exposed to high temperatures are made of 304H material, and the pressure lead pipes are also made of 304H. The three-valve assembly, however, cannot withstand such high temperatures; I’m not sure what to do
If the operating temperature is in a low-temperature environment, it’s not necessary. The medium in the pressure guiding tube does not flow; only heat from heat transfer is present, and it naturally cools down to the ambient temperature after being guided by the pressure tube. Similarly, when measuring low-temperature media such as LNG, the pressure is measured after the LNG is vaporized; the three-valve assemblies of the transmitters are all designed for the ambient temperature.
Shouldn’t the three-valve assembly be next to the transmitter when it’s working properly? So, the temperature needs to be reduced before the three-valve assembly is used.