Steel Pipes - Heat Loss Diagram

Heat loss from steel pipes and tubes (nominal bore 1/2 to 12 inches) at various temperature differences between pipes and ambient air, with correction factors for different installation applications.

Nominal Bore (mm)	Bore Size (inch)	50°C	60°C	75°C	100°C	110°C	125°C	140°C	150°C	165°C	195°C	225°C	280°C
15	1/2	30	40	60	90	130	155	180	205	235	280	375	575
20	3/4	35	50	70	110	160	190	220	255	290	370	465	660
25	1	40	60	90	130	200	235	275	305	355	455	565	815
32	1 1/4	50	70	110	160	240	290	330	375	435	555	700	1000
40	1 1/2	55	80	120	180	270	320	375	420	485	625	790	1120
50	2	65	95	150	220	330	395	465	520	600	770	975	1390
65	2 1/2	80	120	170	260	390	465	540	615	715	910	1150	1650
80	3	100	140	210	300	470	560	650	740	860	1090	1380	1980
100	4	120	170	260	380	585	700	820	925	1065	1370	1740	2520
150	6	170	250	370	540	815	970	1130	1290	1470	1910	2430	3500
200	8	220	320	470	690	1040	1240	1440	1650	1900	2440	3100	4430
250	10	270	390	570	835	1250	1510	1750	1995	2300	2980	3780	5600
300	12	315	460	670	980	1470	1760	2060	2340	2690	3370	4430	6450

Application	Correction Factor
Single pipe freely exposed	1.1
More than one pipe freely exposed	1
More than one pipe along the ceiling	0.65
Single pipe along skirting or riser	1
More than one pipe along skirting or riser	0.9
Single pipe along ceiling	0.75

Calculator

Inputs

Nominal Bore (mm)

Temperature Difference (°C)

Correction Factor

Pipe Length (m) (m)

Results

Heat Loss (W/m)-- W/m

Corrected Heat Loss (W/m)-- W/m

Total Heat Loss-- W