Total Condensate Load (Design)
--
kg/hr
Heat Loss per Meter
--
W/m
Specific Steam Load
--
kg/hr/m
| Pipe OD (NPS) |
-- |
| Insulation System OD |
-- |
| Temp Differential (ΔT) |
-- |
| Steam Saturation Temp (Tsat) |
-- |
| Latent Heat (hfg) |
-- |
Technical Notes
Variable Definitions
-
Q/L (W/m): Heat loss per unit length of pipe.
-
Tm vs Ta: Maintain vs
Ambient temperature. The driving force is ΔT.
-
Safety Factor: Multiplier applied to steady-state
load for trap sizing and startup margin.
Formulas (ISO 12241)
-
Heat Loss (per meter):
Qβ² = (2ΟΒ·ΞT) / ( ln(rβ/rβ)/k + 1/(hextΒ·rβ) )
-
Steam load:
αΉ = (Qβ²Β·3.6)/hfg
(kg/hΒ·m)
-
External convection (screening):
hconv β 5 + 3.9Β·v
(W/mΒ²Β·K, v in m/s)
Standards & Data Sources
-
ISO 12241: Insulation heat transfer methodology
(cylindrical conduction + external convection/radiation).
-
ASME B36.10: Process pipe outside diameters (OD
database used for surface area).
-
Steam properties: Saturation temperature
(Tsat) and latent heat (hfg) via internal
table interpolation (engineering screening).
-
Insulation k: Typical design thermal conductivity
values; confirm final k with vendor datasheet at mean temperature.
Assumptions
- Steady-state heat transfer.
- Steam is dry saturated (quality = 1.0).
- Pipe wall resistance is negligible compared to insulation.
- Insulation dry and intact (no moisture ingress).