Among the four different types of valve actuators, the manual actuator is the most common valve actuators as it can be manoeuvred to practically any position desired but it does not allow automated operations. A manual valve actuator has a hand wheel connected to the valve stem directly or with the use of connecting gears. With gears, opening and closing valves becomes easier. However, the downside of using manual valve actuators is that it requires numerous turns of the gear to create a full turn of the valve stem. The process becomes tasking and at the same time, it lengthens the time spent on opening and closing valves especially those that are bigger in size. However, a manual valve actuator also has its share of advantages. Here are some of them:
- Since manual valve actuators are used with hand wheels, it easily gets attached to the stem when exposed to increased operating temperatures.
- Operating a machine using manual valve actuators is very economical. It only employs gears, levers, and wheels to promote movement. Therefore, there is no need for you to purchase expensive computerized equipment to operate your motors. It only requires labour force and you can start turning your motor to your desired position.
- Manual valve actuators are easy to operate since there are no complex controls or computers attached to it. For as long as you know the basic operations and you have the manual during first use, you can easily open or close a valve without difficulty. However, there are valves that are located in harsh and difficult environments and this makes manual operation impossible including those with extra large valves. In such situation, the other types of valve actuators are excellent options.
- Another advantage of manual valve actuators is that they do not require external power source in order for them to work or to take the motor to your desired position. You don’t need electric power or other source of energy to move the valve. You just need a mechanism that would turn the valve such as a chain wheel, a hand wheel or declutchable device for driving the series of gears. Because manual valve actuators do not require external power, they can be operated anytime especially during emergencies.
- A manual valve actuator is self-contained. It uses the same motion to open or close the valve making it easy to identify errors in the system. It also does not require high technical skill on the part of the operator for the valve to be operated.