Pipeline grade boundary
Thread Content
If the flanges at the pipeline grade transition points are selected according to the higher grade, it will result in a mismatch between the wall thickness of the pipeline at the lower grade and that of the flanges. What is the best approach in such a situation?
At the boundary points between pipeline grades, if selecting flanges of a higher grade results in inconsistent wall thicknesses, it is recommended to use transition fittings or implement strength-enhancing measures to handle the connection between pipelines of a lower grade and flanges of a higher grade, thereby ensuring the safety and reliability of the entire pipeline system. At the same time, reconsidering the pipeline design to optimize the fit between the pipeline and the flange is also an option. .
The flanges at the junction use a lower wall thickness but a higher grade in terms of pound rating.
Can local thinning also be carried out in accordance with the welding specification requirements of GB50236?
The wall thickness of the flange is the same as that of the pipe; flanges of lower quality have a wall thickness similar to that of pipes of lower quality, while flanges of higher quality have a wall thickness similar to that of pipes of higher quality. It’s just that lower-grade flange pound ratings are addressed by using flanges of higher pound ratings