Are you sure about your design temperatures? CPVC is limited to 82 C by B31.3, and at that temperature it has a maximum allowable stress value of 3.4 MPa, barely stronger than bubblegum.

As far as I know, you can buy any fitting in CPVC that you can buy in steel, so you can arrange a piping configuration that is dimensionally identical to what you could do with steel. Your wall thicknesses are going to be a lot higher, though.

If the FRP is the structural element of your pipe, then you will have, in general, different fittings available than in steel. In this case, you will not be able to make an exact dimensional duplicate of a steel piping system, although the differences will in general be small. Also in this case, you may be able to provide higher allowable stresses at your operating conditions.