How to adjust the speed of the cylinder? I want to know the difference between restricting the inlet and restricting the outlet when choosing the speed regulating valve.

The upper and lower joints on the cylinder can be directly replaced by speed regulating joints, and other speed regulating valves are completely free. The so-called speed control valve is to control the speed of the cylinder by controlling the intake and exhaust volume, which depends on how you want to work, so you have to adjust it yourself. There will always be a way you want.