Industrial valves are flow control devices that are used in pipelines and process plants. The valve’s job is somewhat like that of a tap where the flow of the pipeline is controlled by opening or closing the valve. Valve Automation is the process of adding a valve actuator and control system to the valve. Actuators could be powered by human, electric, pneumatic or hydraulic energy.
When a valve uses manual energy, it is operated by hand using hand-wheels, levers and gears. Although they aren’t as expensive as the other options and can be easy to operate, it isn’t always possible or ideal to use this method. Larger valves can be impossible to operate manually due to high thrust requirements and other valves can be located in remote or hazardous environments. It can also be a safety issue if the valve needs to be closed faster than can be done by hand.2. Pneumatic
Pneumatic valve actuators use air pressure, or another gas, as its power source. With its simplistic design, they require minimal maintenance and are used in applications where there are temperature extremes.3. Hydraulic
Similar in operation to pneumatic actuators, hydraulic actuators convert fluid pressure into motion. Suited for high-force applications, they can produce forces greater than a pneumatic actuator of the same size. In some applications, the process fluid itself can provide the hydraulic pressure needed to operate the actuator.4. Electric
The electric actuator converts electrical energy into torque to operate the valve. Offering the highest precision-control positioning, they are also quiet, non-toxic and energy efficient. However, they are expensive and not ideal for critical applications that require high speed or fail modes.
Valve actuators play a major part in automating process control. They can be designed to fail-open, fail-close or fail last. Found in all kinds of process plants, actuators are used in wastewater treatment plants, power plants, mining and nuclear processes, food factories, refineries, and pipelines. Focusing on the Oil & Gas, petrochemical, power generation, mining and aerospace Industries, Cowan offers a wide range of valve actuators designed for severe service.