$(30pt)$ A $4-$nom sch$-40,(D_i=4\mathrm{.}026in,D_0=4\mathrm{.}5in),$ carbon steel pipe $(k_{st}=26Bt\frac{u}{h}r-ft-R)$ with $\frac{11}{2}$

in of insulation $(k_{in}=0\mathrm{.}017Bt\frac{u}{h}r-ft-R)$ carries steam at $440F.$ The convection coefficient

between the steam and the pipe inner wall is $h_i=25Bt\frac{u}{h}r-f{t}^2-R.$ The pipe is above ground and

the convection coefficient between the outer insulation and the air is $h_0=15Bt\frac{u}{h}r-f{t}^2-R.$ The

air is at $60F.$

a$.(10$ pt$)$ Draw the thermal circuit with temperature labels and each thermal resistance on

the circuit. Write the specific form of each thermal resistance on the circuit $($not the

values, that's the next step$)$

b$.(10$ pt$)$ Compute each thermal resistance, and the total thermal resistance, per unit length

of pipe.

c$.(10pt)$ Compute the heat transfer from the pipe, per unit length of pipe.