Motor-operated valves are electric actuated motors used in various kinds of operations. Considering the sizes of the valve actuators, the motor is required to open and close the valve as needed. Therefore, these valves are classified based on opening, closing, and applying. Below are the three main types of motor-operated valves and examples of operations where they are used.
Types of Motor Operated Valves
Open/Close Valves
These motor-operated valves operate on and off basis to turn the water flow on or off. They use precise control to open and close heavy actuators on large valves. They are mainly used in suction valves, drum vent valves, product line valves, boiler feed water isolation valves, and many more.
Inching Valves
Inching valves have more precise control of flow than on/off valves. The motorized actuator allows the opening and closing of the valve to allow some level of control of the flow. They include boiler start-up vents, reflux lines, main steam valves, and IBD valves.
Precision Flow Valves
Precision flow valves are superior to inching valves in precise flow control. This motor-operated valve controls continuous water flow using proper feedback from the field to the controller, unavailable in most motor-operated valves. They include water/steam injection valves used for Nox control in GT.
The difference between the precision flow valves and the inching flow valves lies in the motorized actuator. The actuator operates by the steps configured into the controller in the inching valve. These could be either 5% or 10% opening steps. The flow can also be done within ranges of 5-10% without exceeding the margin of error.
Once you understand the difference between these valves and their ability to control water flow precisely, you can proceed to determine the one that meets your industrial requirements. Heavy-duty operations must use valves with precise flow control without error of margin.
