How to choose the right cylinder models!

Cylinder model selection, the main hydraulic cylinder inside and pressure.
For example:
1) stroke 300MM, thrust 4000KG, the choice of which type of cylinder?
Press 4 tons of thrust, can be calculated, if the cylinder pressure is  designed to 8MPA, the inner diameter of the cylinder 80, the cylinder  model 80 * 40 * 300-8MPA, can tie rod cylinders, low cost, easy  maintenance.
If the cylinder pressure selection 16MPA, the inner diameter of the  cylinder 60 can be, the cylinder model 60 * 35 * 300-16MPA, can be  welded or tie rod.
The proposed combination of system pressure mechanical equipment, make sure the cylinder pressure. Machinery and equipment for finishing, then select the system pressure  is lower, usually in 5MPA less, if rough, then the system pressure is  selected larger.
Determining  the system pressure equipment, projected to go inside diameter of the  cylinder, and then decide cylinder connection, installation, rod end  thread, install the specific dimensions and the like. Of course, installation of the cylinder and also the process of  estimating the relationship, such as the cylinder is mounted vertically,  horizontally mounted, or angled.
2) with two hydraulic cylinders for the top 4t lifting weights  movement in the vertical direction, a stroke of 2000mm, ask how to  choose the cylinder?
Important parameters of the hydraulic cylinder: Bore, stroke, pressure (or force).
Bore and pressure are two variables, such as bore 50, the use of  pressure 12MPA, can reach two tons force; for example, bore 63, the use  of pressure 7MPA, can reach two tons force.
The pressure in turn depends on your hardware system pressure, system  pressure to see your precision machining equipment, precision machining  equipment low pressure system can be set larger.
So to choose a hydraulic cylinder, the first device to determine the system pressure.
Requirements  in exceptional cases the weight does not fall within the fuel tank  leakage ---- higher requirements, and the hydraulic system, but also to  ensure that configuration.