The objective of this work is to present an application of the simulated annealing method for the optimal design of pipe networks including pumps. Although its importance, the optimization of pumped networks did not receive great attention in the literature. The proposed search scheme explores the discrete space of the decision variables: pipe diameters and pump sizes. The behavior of the pumps is describe through the characteristic curve, generating more realistic solutions. In order to demonstrate the versatility of the approach, three different examples of optimal design problems are solved.