Do not base your job safety and life of users on comments from an unknown counselor!
If you do not have the knowledge to do this job hire a specialist or buy a cylinder from a specific manufacturer.
I could give you the values but it is unsafe since I do not know how you will use them and a cylinder burst at 450 bar can be deadly for many around.
High pressure is not a game.
Not only design is important but as well how you will manufacture and test it, the kind of seals, the surface treatment, its roughness expected velocity aso.....
Sorry to send same message but it came when I wrote mine!
Re: Hydraulic Cylinder