13.2-4. Convection, Conduction, and Overall U. A gas at 450 K is flowing inside a 2-in. steel pipe, Schedule 40. The pipe is insulated with 51 mm of lagging having a mean k = 0.0623 W/m · K. The convective heat-transfer coefficient of the gas inside the pipe is 30.7 W/m2 · K and the convective coefficient on the outside of the lagging is 10.8. The air is at a temperature of 300 K. a. Calculate the heat loss per unit length of 1 m of pipe using resistances. b. Repeat, using the overall Uo based on the outside area Ao