You are entirely correct, but it is quite difficult to actively discriminate between the two. It is best to take the view that they are both very very dangerous (or rather, have the potential to be if mistreated) and extreme care and caution must be taken which designing and building both systems. If either of the systems to fial, lets hope its in the arena. To give an idea of the magnitude of the mess of a system failure, I would point you towards whichever heat it was whan Spawn Again losts its End cap when running a Low pressure ram on Full Pressure. Certainly not something youd want to happen in your garage, but nothing the arena couldnt cope with.

I have a question based on what weve acheived above in the conversation: should I treat my purpose build ram as a hydraulic one when interpreting the rules? Or should i just be safe and pressure test it to 200Bar?