A steel pipe (outside diameter 100 mm) is covered with two layers of insulation. The inside layer, 40mm thick, has a thermal conductivity of 0.07 W/(m K). The outside layer,20mm thick, has a thermal conductivity of 0.15 W/(m K). The pipe is used to convey steam at a pressure of 700 kPa. The outside temperature of insulation is 24°C. If the pipe is 10 m long, determine the following, assuming the resistance to conductive heat transfer in steel pipe and convective resistance on the steam side are negligible: a. The heat loss per hour. b. The interface temperature of insulation.