The discussion revolves around the thermal expansion of piping systems, specifically focusing on the comparison between using a linear coefficient and an area coefficient when accounting for diameter expansion. Participants explore literature references and technical standards related to piping flexibility analysis and the implications of thermal expansion on stress and deflection in piping systems.
Participants express differing views on the relevance of diameter expansion in stress analysis, with some emphasizing its lesser importance compared to length expansion. There is no consensus on the appropriateness of using the same linear coefficient for both diameter and length changes.
Participants note that the analysis of thermal expansion in piping systems is complex and dependent on various factors, including material properties and support conditions, which may not be fully addressed in the discussion.
Most piping systems in the US must conform to ASME B31.3 "Process Piping Code". Para. 319 covers concepts, requirements and equations to be used for piping flexibility analysis, especially those stresses and deflections due to thermal expansion/contraction.Can anyone offer a literature reference regarding thermal expansion of piping systems?
Can you be more specific? Are you referring to the coefficient of thermal expansion/contraction?I am interested in reading up on how the use of a linear coefficient compares with using an area coefficient when accounting for diameter expansion.
Metals can be modeled as isotropic materials, so yes, the coefficient of thermal expansion/contraction will be the same for both length and diameter of a pipe.I was trying to figure out if the same linear coefficient for expansion/contraction can be used to estimate a diameter change as well as a length change (which I have seen done in the past).
Right, and of course how the piping system will react also depends on how it is supported - for example: where the pipe is anchored (fixed point) or allowed to slide or otherwise supported.... the real concern is with the bending loads due to length expansion.