More than a hundred of valves are being used in power plants in various stages of operation. These valves are usually operated in tough environments and are readily exposed to chemicals and varying temperatures. In conjunction with an actuator that controls it, valves are used for chemical treatment and pollution control, among others. Its use provide optimum efficiency to the operation of a power plant as a whole. Today, demands for Belimo actuators & valves have become greater as power plants are expected to adopt to the flexibility of growing sources of renewable energy.
How It Works
The control valve as a single unit is composed by an actuator and valve. Actuators do various sequences like linear and pivoting motions and are powered by electrical, pneumatic or hydraulic energy. Automation systems provide the control signal for an actuator. This signal is turned into motion which becomes the controlling element for the actuator to move accordingly.
Types of Actuators
The common types of actuators are hydraulic, pneumatic and electric. Pneumatic valve actuators are energized by gas or air. This type of actuator is usually used by power plants in controlling their valves. The advantages of pneumatic actuators include faster stroking speeds, low risk for fire, lower cost and dependability. However, it may not give out the best performance during slow speeds. Precise control may also become impossible due to inconsistency once air is compressed.
Pressurized hydraulic fluid is used by hydraulic actuators to close and open valves. This type is becoming more popular due to its ability to reach high torque. Hydraulic actuators are designed to provide linear movements. Hydraulic actuators are known to be more powerful than pneumatic types. It also gives you definite control as it is also capable of turning small input pressure into bigger outputs. For hydraulic actuators, efficiency is greatly influenced by temperature changes. It is also more expensive and is a potential hazard for fire.
Electric control-valve actuators have achieved great improvements since it was developed. It helps power plants increase efficiency and trim down costs. Belimo actuators & valves have developed and distributed electric actuators that are used for dampers and valve technology for air conditioning systems and heating systems, as well.
Valve actuators that are powered by electric motor are in demand due to its durability even when exposed to harsh environments. It requires less maintenance and further enhance the performance of the control valves. It doesn’t even need regular recalibration as electric actuators are able to operate without tuning for years.
The complex nature of power plants requires it to be flexible in terms of sub systems. Due to the strenuous and demanding environment, it is expected that various technological practices will also be implemented to maintain reliability and efficiency. One key to achieve maximum performance is through the use of control valves. Choosing powered actuators requires you to know various parameters like stroke length and timing, among others. Considering that a single facility often requires a large number of valves in its operation, it is imperative that the safety of personnel should be given the highest regard.