Control Air Flow of Cylinders
Output force of a pneumatic cylinder is function of air pressure as cylinder speed is function of its air flow.
s = 28.8q / A
where s = speed (inches per second); q = airflow in standard cubic feet per minute (SCFM); and A = piston area, in²
*(Note: inlet pressure must be held constant)
However, controlling the air flow of a pneumatic actuator is not the sole factor in determining its speed. Other factors that may affect a pneumatic actuator’s speed include port and tubing sizes.
The most common industry practice to control the air flow of a pneumatic actuator and hence its speed is to control the flow rate at the actuator’s exhaust port. The resulting decreasing or increasing in back pressure causes the actuator’s piston to travel at a faster or slower speed which is usually controlled by installing a meter-out flow control or needle valve.