eli5: If water is non-compressible, then why not use it in hydraulic machines instead of hydraulic oil?

Question

eli5: If water is non-compressible, then why not use it in hydraulic machines instead of hydraulic oil?

In: 1817

Answer 1

Water has a couple of problems that are particularly important when thinking about machinery

– It freezes below 0°, and boils at 100°. That’s a very specific temperature, and its performance will vary within that range. If it gets too cold, your machine is almost certainly broken because of ice expansion. If it gets too hot, it can cease to be a liquid; your hydrolyic machine just became pneumatic.

– Water is corrosive. Extremely so. It’s known as the universal solvent for a reason; This stuff tears down mountains, and reduces the ocean floor to loose sand.