This paper describes a user-friendly software for the calculation of general piping system networks composed of virtually any parallel and series pipe arrangement. Solution of the network is made with recourse to the iterative method of Hardy Cross. Solution is provided for pressure and flow-rate in each branch. Dimensioning problems, where pump characteristics or a pipe diameter are sought for achieving a pre-specified flow-rate condition, may also be tackled. 2004 Wiley Periodicals, Inc. Comput Appl Eng Educ 12: 117 125, 2004; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20006