Water Hydraulics

As I'm looking at a more modular design power deliver for machinery is becoming important. Low pressure water hydraulics could be a good fit. Water at around 200 psi should be able to deliver plenty of power with out the need for expensive equipment.

Water needs to be treated to prevent bacterial grown. There will need to be a filter in the system. Temperature will be a concern and anything exposed to cold temperatures will require heating.

Schedule 80 pvc pipe at 1.5" can handle almost 300psi, so running at 200psi leaves a large margin of safety.

Pex isn't rated as high, but in a test video, it was surviving well above 500psi, again 200psi should be fine.

I think pistons can be built with pvc pipe. Pumps and motors can either be 3D printed or be built around pistons. In particular, centrifugal pumps may fit well because they can't exceed pressure limits. Another interesting way to do this would be a swash plate piston pump with a spring pulling it towards high flow and a piston pushing it low. With this, the system will self regulate.

I'm interested in magnetic coupling - this could eliminate the need for seals around moving components.