The pressure rating of the piping system will have to be greater than the highest pressure in the system. The greatest pressure in this system is at the pump discharge. The pressure at the pump discharge is 20psi + Δp_pump, where Δp_pump is the pressure rise across the pump. With the given...
That drawing is what is called Crossreferenced (Xref). You need to download the background drawing/s as well and save it to the same directory of the lighting drawing.
I do agree with your solution. However, You could have just done P1 at the pump discharge and P2 the outlet of the pipe. Just a quicker way to the solution.
Mike
I typically use the equations I am used to. the ultra common Q=1.08*CFM*(T2-T1) for air or Q=500*GPM*(T2-T1).
I only convert the mass flows if it requires that for an answer.
The air tables are the fastest and most accurate things to use. That equation is for constant entropy process as well. Best to stick and get used to the tables. TIME SAVER.
You are given the actual Inlet (T4) and Outlet (T5) Temperatures in the table. It is simply not needed.
You are given all the temperatures for the Regen. except for T3. T3 is what you need to find to solve the problem for the thermal efficiency of the cycle.