Problem:
A steel pipe carrying steam has an outside diameter of 89 mm. It is lagged with 80 mm of insulation having an average k = 0.043 W/m-K. Two thermocouples, one located at the interface between the pipe wall and the insulation and the other at the outer surface of the insulation, give temperatures of 120 and 30 °C, respectively.
Required:
Question: Calculate the heat loss in W per m of pipe.
Note: Please show how to work it out.