Pneumatic cylinder Faq

Hi folks
i need some education on pneumatic cylinders.Does pneumatic cylinders have definite speed at which they move like Dc linear actuators?For instance most manufacturers of Dc linear actuators quote the speeds of the actuators eg 10mm/sec etc.
When the load of a cylinder is high/more,does it slow down the rate of movement of the cylinder like is the case with 12V Dc linear actuators?If not ,how can the speed of cylinder be slowed?Is possible to slow it down with a shock absorber?
Most Dc linear actuators can be reversed with DPDT switches but How is a cylinder reversed ?

Yes of course load will slow down an actuator, that's basic physics, doesn't matter that type of system that's applying the energy. Pneumatic cylinders will have a definite speed with a known load if given a constant pressure, but real world systems get complicated, if you feed a pneumatic cylinder a pulse of energy (air) it's output pressure will be anything but linear, you can definitly use shocks to absorb the energy but a more common method is simply using plugs with various hole sizes to act as pressure limiters, this is how the air shocks work. Not all pneumatic cylinders can be reversed, you can of course apply a vacuum, however this has a limitation of the vacuum to hold the load, you need double acting pneumatic cylinders which have two ports to allow pressure to be applied on both sides of the piston.

https://en.wikipedia.org/wiki/Pneumatic_cylinder

There are probably hundreds of thousands of speed controlled cylinders in auto assembly plants world wide.
With a suitably sized cylinder for the application, they will run so close to a constant speed, you will never know the difference. Kinda like turning on an LED with a car battery, the voltage doesn't flinch. You can buy/make a simple/cheap "speed control" (that's their real name) that attaches to the cylinder ports. Those along with tailoring the supply pressure will make the cylinder very speed controllable.
Because they're mechanical, nose seals wear out quite often, piston seals not so much. A lubricated air supply helps too.
To do what some of them do electrically would cost almost 50X as much.