A $240$mm diameter cylindrical steam pipe, $210$m long is covered with $50$mm of high

temperature insulation k$=0\mathrm{.}092$W$/$m C and $40$mm of low temperature insulation

k$=0\mathrm{.}062$W$/$m C$.$ The inner and outer surface temperature as measured are $390$C and $40$C

respectively.

Calculate $1.$ Total heat loss per hour $2.$ Temperature between two layers of insulation.