Automated valves can be classified based on there actuation method. There are many ways to actuate a valve however generally used methods are listed below.

Pneumatic –

• Valves which are operated using Air or gas pressure are called Pneumatic valves.
• In case of linear valve air pressure acts on the obturator creating linear pressure.
• In case of rotary valve air pressure generates torque to provide rotary motion.
• Availability of compressed air on the site is the most important factor while going for pneumatically actuated valves.

Electric –

In case of electrically actuated valves, electric motors are used. Here availability of electricity at the site becomes major deciding factor.

Hydraulic –

• Hydraulic actuators use fluid pressure to actuate the valve.
• In case of linear valve, fluid pressure acts on a piston providing a linear thrust.
• In case of rotary valve it provides the torque for rotary motion.

Positioners are used to give command to control the valve for opening, closing or to maintain any intermediate position.

Capacity of the actuator is totally depends on two parameters

• Size of the Valve
• Quantum of force actuator is able exert.

In case of rotary actuation this force is called as torque and in case of linear actuation same is called as thrust.

typically Automated valve comprises of Actuator, Valve, Mounting arrangement, power transmission element and an option to manually override the actuator operation.

Valves which are operated without any manual efforts are automated valves. Automated valves can be actuated with the help of Pneumatics, hydraulics, electrically or with a combination of these.

By the type of movement

• Multi-turn
• Quarter-turn
• Linear

By the energy source

• Manual
• Electric: they can be driven by direct and alternate current.
• Pneumatic: they use pressured air or gas to create motion. They are widely used in the industry due to their low cost. In case of failure they are easy to diagnose or repair in field, rather than electric actuators.
• Hydraulic and Electro-Hydraulic

Functionality

• On/Off valve service
• Positioning to % open
• Modulating to control changes on flow conditions
• Emergency Shut Down (ESD)

Other characteristics

• Explosion-proof
• Safety integrity level (SIL)
• Enclosure: IP and NEMA

Actuator is a device that transforms or converts energy into motion.

Also applied as a force, an actuator usually is a mechanical apparatus that takes energy, normally constructed by air, electricity, or liquid and converts that into a specific kind of motion.

Actuators are a type of tool which is used to put something into automatic action.

Automation is the techniques and equipment used to achieve automatic operation or control.

Automation is an automatic operation and control of machinery or processes by devices, such as robots that can make and execute decisions without human intervention.

Automation is the great idea of industries. After introducing Automation the quality of the product is increased. The controlling logic and process methodology where has been taken care by automation systems.