T steady state, a valve and steam turbine operate in series. The steam flowing through the valve undergoes a throttling process. At the valve inlet, the conditions are 600 lbf/in.2, 800oF. At the valve exit, corresponding to the turbine inlet, the pressure is 300 lbf/in.2 At the turbine exit, the pressure is 5 lbf/in.2 and the temperature is 200oF. Stray heat transfer and kinetic and potential energy effects can be ignored. Determine the work developed by the turbine, in Btu per lb of steam flowin