Pipe Cold Spring (Cut-Short)
Free thermal growth, the cold-spring gap to cut the run short.
Example
You enter
- Material (sets coefficient) steel
- Run length (ft) 100
- Install temperature (°F) 50
- Operating temperature (°F) 250
- Cold-spring factor (%) 50
You get
- Free thermal growth 1.56
- Cold-spring gap (cut short) 0.78
- Residual movement / per 100 ft 0.78
Details, formula, and sources
Free thermal growth, the cold-spring gap to cut the run short, and residual movement for a pipe sprung into place at install temperature (ASME B31.1 §119).
Free growth dL = alpha * L * dT (alpha per material in/in/F, L in inches, dT = |T_operating - T_install|); cold-spring gap = (factor/100) * dL; residual movement = dL - gap.
Pipe cold spring (cut-short) - the run is cut short by a fraction of the computed free thermal growth and sprung into place at the install temperature, lowering the hot anchor and equipment-nozzle reactions - per ASME B31.1 Power Piping §119 / B31.9 Building Services Piping, by name; first-principles linear expansion.
First-principles linear expansion. Cold spring does not reduce the cyclic stress range (B31.1 §119.10); B31.1 credits two-thirds of the cold spring in the reaction. The piping engineer governs the flexibility analysis.
Estimate. AHJ and licensed mechanical contractor govern. ACCA Manual J / D / S supersede rules of thumb.
Field names used by the API: material, run_length_ft, install_temp_f, operating_temp_f, cold_spring_percent, thermal_growth_in, cold_spring_gap_in, residual_movement_in
- Expansion coefficient alpha per material: steel 6.5e-6, copper 9.4e-6, PVC 3.0e-5, PEX 1.1e-4 in/in/F (matches the sibling tile); user-overridableASME B31 / manufacturer bulletins