Pipe Thermal Expansion and Loop Sizing

Linear expansion plus the guided-cantilever expansion-loop leg L_loop = sqrt(3 × E × D × dL / S_a).

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Formula and source

Linear expansion: dL = alpha × L × dT (alpha in 1/°F). Guided-cantilever expansion loop leg: L_loop = sqrt(3 × E × D × |dL| / S_a) where E is Young's modulus (psi), D is pipe OD (in), S_a is the allowable stress (psi).

ASME B31.1 / B31.9 (Power and Building Services Piping) guided-cantilever method by name. Per-material alpha / E / S_a from data/plumbing/thermal-expansion-coefficients.json.

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