The selection of valve actuator type by its power source shall consider several issues as follow:
Service in process system
Mode of operation such as on-off or throttling operation. The requirement of valve closing or opening time.
Remote valve location
For pipeline in the middle of nowhere, pneumatic actuated valve with supplementary air or nitrogen bottle which periodically inspected is the only posibility.
Process requirement of valve to fail open, fail close or fail last. Standard motor operated valve will be fail last when loosing power supply.
Valve operating torque
The actuator torque shall be larger than the required torque by valve in specified operating process and condition. Safety factor shall be taken into account in selecting the size of the actuator.