Selection of allowable stress for pressure strength verification of pressure pipelines
Thread Content
Assuming that the material of a pressure pipeline is 10#, and the standard designation is unknown, should the allowable stress be determined based on the lowest strength value (yield strength and tensile strength) for materials of the same grade, or should it be chosen based on the minimum allowable stress value? How should the priority levels be chosen? Are they allowable stress > yield strength > tensile strength?
In the design of pressure pipelines, the commonly adopted principle for selecting the allowable stress is to choose it based on the lowest strength (yield strength and tensile strength) of similar grades. This is because the strength of steel of the same grade falls within a certain range, and variations in its strength are related to factors such as production batches and processing techniques. Therefore, if the selection is based on the minimum allowable stress, a strength value that is too high may be chosen, leading to overuse and a decrease in safety. The selection of priority levels should be based primarily on safety, to ensure the reliability and safety of pipeline usage. Therefore, when selecting the allowable stress, the lowest strength of similar grades should be given priority. Of course, in practical applications, it is necessary to take into account various factors such as design conditions, operating environment, and pipeline materials in order to ensure the safety and reliability of the pipelines. .
If the standards are not clear, should the thickness be taken into account when selecting the allowable stress?
The standards are not clear; the selection of allowable stress requires consideration of factors such as the material’s strength and thickness. Generally speaking, the mechanical strength of steel is limited and cannot exceed its maximum allowable value. At the same time, the wall thickness of the pipeline must also meet the requirements regarding material strength and the internal and external pressures of the pipeline. Therefore, when selecting the allowable stress, in addition to considering the lowest strength of similar grades, the thickness of the pipe also needs to be taken into account to determine an appropriate allowable stress value. For pipes with a larger thickness, their stress characteristics differ from those of thin-walled pipes. Under such circumstances, design calculations such as strength checks are also required to ensure the safety and reliability of the pipeline. Therefore, when the standards are not clear, the thickness of the pipe also needs to be taken into account when selecting the allowable stress, in order to ensure the rationality and safety of the pipe design. .
The guy is amazing – concise and easy to understand. I didn’t consider that at first