A simple water-using network with single internal water main based on water pinch analysis is presented. The processes are arranged as sources of the internal water main according to the relative outlet concentration. First, the initial water-using network is set using the processes below and at the pinch as sources of internal water main. Then, the sources are added or reduced according to the relative outlet concentration until the restricted process is determined. Finally, fresh water consumption of water-using network is minimized when the amount flowing into the internal water main equals to the reused water allocated to the sinks. The Case studies show that the designs in this work are comparable to that reported in the literature. Comparing with other design methods, the presented method is simple and effective.
