Water Line Transmission of Control Information

The hydrodynamic relations of flow and pressure are used to transmit information over a ten mile long, small diameter transmission main. The system includes an inlet rate of flow controller on the terminal reservoir, so designed that the rate of inflow into the reservoir is dependent only on the level of the water in the reservoir, and will not normally be affected by the pressure in the transmission main. Selection of the well pump being used is determined by the rate of flow of the water into the reservoir. The output pressure of the pump is regulated by varying the speed of the engine driving the pump. The engine speed is controlled by a preselected head-discharge relationship of the transmission main, and is controlled in such a manner that the pressure on the control valve at the reservoir inlet will be between 20 and 40 psi. The entire system operates with only an occasional checking or mechanical service call.