pressure reduction through process

I am planning on using a Ø2.5 cylinder with 1.125 Rod Dia. Maximum operating pressure of 1500 PSI.
Pushing an Ø8.375 piston through a proposed Stainless Steel 304 pipe with .148 wall. Operating pressure is usually 1000 PSI(in a shd-40 pipe). Since the burst pressure is about 3800 PSI, this referring to the total Square surface area in sq. in. that will be under compression, this is what I need to be aware of, right?

Diagrams please! Too many opportunities for misinterpretation. Also sounds like you are mixing (or misunderstanding) your units.