How to Control the Speed of an Actuator
The speed control of actuators in pneumatics is achieved by regulating the flow rate. This is typically done by reducing the cross-section at a specific point. For this purpose, flow control valves are used.
As a general rule, the exhaust air from the actuator should always be regulated, as this ensures a smooth and jerk-free movement. Regulating the incoming air can lead to malfunctions and should be avoided.
Speed control can be achieved using throttle check valves or throttle silencers.
Example 1: Speed Control Using Block Form Flow Regulators (F1.1 and F1.2)
In this example, the exhaust air is regulated via one of the block form flow regulators. These valves are installed between the pilot valve and the actuator. The actuator speed is adjusted via a spindle on the regulator. This method is suitable for applications with medium to high accuracy requirements for positioning speed. The HAFNER flow regulators of type "DR" are particularly recommended for this purpose.
HAFNER DR801 flow regulator
View block form flow regulators in the online catalogue
Example 2: Speed Control Using Flow Control Silencers (F2.1 and F2.2)
Here, the exhaust air is regulated via one of the two flow control silencers. These silencers are screwed directly into the exhaust ports of the pilot valve. The actuator speed is adjusted via adjustment screws. This method is suitable for applications with lower accuracy requirements for positioning speed. The HAFNER flow control silencers of type "SVE" are optimally suited for this purpose.
HAFNER SVE flow control silencer
View flow control silencers in the online catalogue
Speed Control for Quarter-Turn Actuators with NAMUR Interface
For quarter-turn actuators, speed control using block form flow regulators in combination with NAMUR pilot valves is not possible. Special NAMUR flow regulator plates are available for this purpose, enabling precise adjustment of positioning time.
For single-acting actuators, the opening and closing speed can only be adjusted independently using a flow regulator plate.
For double-acting actuators with no high positioning time requirements, regulation can alternatively be achieved using flow control silencers (see above).
NAMUR-compatible flow regulator plate