creating series output-reg

Dear All,

For my problem i want to create one inlet and two outlets in series 

For example: I want to calculate the flow in a pipe of 1m in that inlet is 5 bar and the outlet is ambient but i want to control the pressure in the middle of the pipe at .5m say 4 bar ( i,e 1 bar pressure drop)

How to set the boundary conditions for this problem ?

kindly provide your guidelines

Thanks

Ram