Neutron-absorbing control:

Last control elements are devices which finished the control loop. They connect the output of the controlling elements along with their processes. A few last control elements are designed for specific applications. For instance, neutron-absorbing control rods of a reactor are specifically designed to regulate neutron-power level. Therefore, the majority of last control elements are common application devices such as valves, pumps, dampers, and electric heaters. Valves and dampers have same functions. Valves regulate flow rate of a liquid when dampers regulate flow of air and gases. A Pump, like valves, could be used to control flow of a fluid.  Heaters are used to control temperature.

These devices could be arranged to give a type of "on-off" control to manage a variable among maximum and minimum values. This is accomplished through opening and shutting valves or dampers or energizing and de-energizing pumps or heaters. Alternatively, these devices could be modulated over a provided operating band to give a proportional control. This is accomplished through positioning valves or dampers that varying the speed of a pump, or regulating the current by electric heater. There are several options to a process control.

Of the last control elements discussed, the most hugely used in power plants are valves. Valves could be simply adapted to control liquid level in a tank, temperature of a heat exchanger and flow rate.