A control loop is a process management system designed to maintain a process variable at a desired set point. There are different types of control loops, such as cascade control, override control and the split range control loops
These control loops are used in process control according to the process nature. Let's discuss about the split range control loop.
A split range control loop is used, where there are several manipulated variable and single output variable.
So that, each control elements need separate control signals.
The manipulated variables are coordinated by the split range control.
In above picture the team header must be maintained at constant. The pressure controller splits the control action and given to the valves simultaneously in parallel for a combined control action.
For example, for a usual control system with one valve is implemented for a particular process, the control action needed is 80% valve open. In split range loop this action is splited into two control action for two control valve, that is one valve will be manipulated to 40% open and another 40% open for next valve..