A 240 mm dia. steam pipe, 200 m long is covered with 50 mm of high-temperature insulation of thermal conductivity 0.092 W/m-K and 50 mm low-temperature insulation of thermal conductivity 0.062 W/m-K. The inner and outer surface temperatures are maintained at 340°C and 35°C respectively. Calculate the following in the SI unit:

a. the total heat loss per hour,

b. the heat loss per m2 of pipe surface,

c. the heat loss per m2 of outer surface,

d. the temperature between interfaces of two layers of insulation.