If you take an unmodified standard hydraulic ram, you can use it on pneumatics to a pressure level of 50% of the rams hydraulic rating or 1000 psi - which ever is the lower without requiring further test certification. It is permitted to mod the ram as long as those mods cannot affect the pressure integrity of the ram. Cushioning is a common mod undertaken to absorb some of the dynamic forces.

You can use gas or fluid to pressure test the ram, if using oil you will need to clean / flush the oil out afterwards.

Paul
FRA Technical Team