Urgent! ! What material is the L390 pipeline made of? What is its allowable stress?
Thread Content
In the qualification examination for pressure pipelines, there is a question related to calculating the pipe wall thickness; the pipe material used is L390, and since its allowable stress is unknown, it’s difficult to proceed.
The allowable stress is actually determined by the designer themselves, based on different loading conditions and operating environments... For plastic materials, it is calculated by dividing their yield strength by a corresponding safety factor. The choice of this safety factor takes into account factors such as the designer’s experience, the accuracy of the stress analysis, and any stress concentration in the material. I believe that the selection of allowable stress is one of the indicators that best reflects a designer’s skill level. The strength limit σb of brittle materials and the yield limit σs of plastic materials represent the ultimate stresses under which a component can function properly. In engineering practice, these ultimate stresses are divided by a coefficient n greater than 1, and the resulting value is used as the material’s allowable stress [σ].