For pipes at 650 degrees, is stainless steel 304 suitable?
Thread Content
I’m currently facing this issue: it relates to a pipeline in the syngas plant used for producing methane, running from the reactor outlet to the heat exchanger. The design temperature of the pipeline is 650 degrees, the design pressure is 4.0 MPa, the material is S30408, and the wall thickness is 14 mm. May I ask if this material is suitable for this operating condition? Thank you! Please ask an expert to explain the reason.
It’s a bit tight; at 650°C, the allowable stress for 30408 is approximately 42 MPa. Choose other materials! ?
The design pressure is 4.0 Mpa, not 40.
The design pressure is 4.0 Mpa, not 40.
The specification allows up to 42MPA, so there’s no problem at all
A wall thickness of 14 mm is insufficient for diameters above DN200. Additionally, the use of austenitic stainless steel at high temperatures is limited; for specific requirements, refer to GB/T 20801.2. It’s recommended to change the material.
This time it’s a DN150 pipe
According to clause 6.2 of GBT20801.2 regarding material selection, option f) – pipes made using a 650-degree processing method – should be used; the use of 304 steel is not recommended. If 304 steel is to be used, then 304H should be chosen, ensuring that its carbon content is 0.04% or higher, and it should be used in its solution-treated state. GBT208.1.2 Code for pressure pipelines — Industrial pipelines, Part 2: Materials; accordingly, the high-temperature brittleness of austenitic stainless steels also needs to be taken into account
I don’t know much about the production of methane from syngas; I’m not aware of what the temperature at the reactor outlet is
Choose other materials for operating conditions at 650 degrees Celsius. . .