How to use
Enter metal outside diameter and length. Choose pipe or tank with two flat ends; compare thickness A/B using the same k, h and temperatures.
Example calculation
D = 100 mm, L = 2 m, h = 10, 80→20°C, bare pipe: approximately 376.99 W.
Calculation method
R_c = ln(r₂/r₁)/(2πkL) + 1/(h·2πr₂L) Q_c = |Ts−Ta|/R_c; r₂ = r₁ + t R_e = t/(kA) + 1/(hA); Q_e = |Ts−Ta|/R_e Q_pipe = Q_c; Q_tank = Q_c + 2Q_e r₁, r₂, L, t: m; A: m²; Q: W
Calculation limits
Steady 1D conduction and outside convection at fixed metal temperature. Excludes radiation, metal/internal-film resistance, bridges and end edges. Negative reduction is possible through the critical-radius effect.