|
|
|
|
|
| Actuators are used to operate valves and dampers automatically and/or remotely. Actuators typically use pneumatic, electric and hydraulic power to actuate a valve shaft. The force output of the actuator must be sufficient to overcome valve static friction and dynamic torque. Static friction is developed in the metal-to-metal surfaces, seats, and seals. Dynamic torque is that unbalanced force of the process acting on the plug, disc, or ball. Valve torque requirements are supplied by the manufacturer and based on pressure drop across the valve. A minimum of 20% safety factor should be added to insure reliable operation. The on/off actuator positions the valve in the open or closed position. Modulating actuators use controllers/positioners to maintain a valve position based on an input signal. |
|
|
|
|
A-T Controls
