A steel pipe 25 mm id, and 33 mm od, and insulated with rockwool carries steam at 178C. If the surrounding an temperature is 21C. Calculate the rate of heat loss from one meter length of pipe. The thickness of insulation is 38 mm. Thermal conductivity of steel and rockwool are 10.74 and 0.0418 cal/sec m C respectively. The inside and outside heat transfer coefficients are 1356.17 and 2.7133 cal/secmC respectively. Contact resistance between the pipe and insulation may be neglected.