When Rotork Gears’ company Exeeco were asked by United Utilities to solve a “dry bedding” sand filtre problem at water treatment works serving the NW of England, they were able to submit a solution using Rotork Skilmatic actuators. The problem was recognised after several power failures had led to “dry bedding” in filtre beds, caused by delayed closing of outlet valves,
jeopardising the quality of the water reaching the reservoirs. It was decided that the process needed to detect a power failure in order to put the treatment plant inlet and outlet valves on “standby” until the back-up generators cut in. On some of the pumping stations an uninterrupted power supply (UPS) was the obvious solution, but this was deemed to be too costly and require
too much maintenance to be seen as the universal solution. However, these drawbacks could be overcome using Rotork Skilmatic failsafe electric actuators. The Skilmatic actuator is a totally self-contained failsafe electro-hydraulic design capable of continuous modulation duty and failsafe action on loss of signal or power supply.
