When choosing an air cylinder shock absorber, you can consider things like:
Force
The force a cylinder generates is a key selection criterion. You can calculate this by looking at the cylinder's air pressure and bore size. A general rule of thumb is that the force should be twice the load for vertical and high-friction applications.
Bore size
The bore size should be 1.5 to 2 times the diameter of the load being moved. An oversized cylinder can be more expensive, while an undersized cylinder might not be able to move the load.
Cushioning
Heavier-duty cylinders, or those with strokes longer than three or four inches, often have extra cushioning to handle larger loads and dynamic forces. Most cylinders come with elastomer cushions, also known as bumpers, either as an option or standard.
Here are some other tips for selecting a pneumatic cylinder:
Get an accurate air-pressure reading
Calculate the actuator's overall length and working stroke
Know the effects of resulting torques
Calculate the effects of dynamic moment loading
Understand the difference between impact and average velocity
Calculate the cushion or shock absorber capacity
Consider the effects of motion lag due to breakaway, friction, and acceleration forces
Size for horizontal or vertical applications
Know the environmental conditions