Hydraulic systems ques

[potrack]

Why are most aircraft hydraulic systems 3,000psi?

Why 3,000? Why not higher pressure or lower pressure?

 

[CougarAviator]

C172RG is 1000-1500 psi....

 

[Clyde]

Why are most aircraft hydraulic systems 3,000psi?

Why 3,000? Why not higher pressure or lower pressure?

3000 psi is more than adequate to operate the systems of most large aircraft. The pumps themselves can actually put out more than that, I've been told up to 5000 psi in some cases.

The big reason that I've heard why you don't see many hyd systems greater than 3000 psi is for safety. The higher the pressure, the greater the risk for increased damaged if something goes. Plus, you need tougher hardware to be able to handle all of that pressure and that means more weight.

 

[80/20]

To expand a bit on Clydes good explanation I would say that hydraulic system design considerations are mostly focused on weight of pumps, actuators, fluid volume and plumbing. The force of the hydraulic actuator depends on pressure and the size of the piston where the fluid pressure is applied. A 5000 psi system can use smaller actuator pistons than a 2000 psi system but the 5000 psi system will require thicker hydraulic lines. 3000 psi will give a good power to weight ratio for the components and required liquid volume needed in a typical transport category jet.