(a) How will untreated water affect the efficiency of heating equipment? (b) Steam at T1320C flows in a cast iron pipe (k=80W/mC) whose inner and outer diameters are d15cm and d25.5cm, respectively. The pipe is covered with 3 -cm-thick glass wool insulation with k=0.05W/mC. Heat is lost to the surroundings at T2=5C by natural convection and radiation, with a combined heat transfer coefficient of h2=18W/m2.C. Taking the heat transfor coefficient inside the pipe to be h160 W/ m2C, determine the rate of heat loss from the steam per unit length of the pipe. [1+3]