The amount of non-revenue water is around 126 billion cubic meters annually worldwide mostly due to leakage. A more efficient wastewater management strategy would use a parametric design for on-demand customized pipe fittings, following the principles of distributed manufacturing. To fulfill this need, this study introduces an open-source parametric design of a 3D printable easy connect pipe fitting that offers compatibility with different dimensions and materials of the pipes available in the market. Custom pipe fittings were 3D printed using a RepRap-class fused filament 3D printer, with polylactic acid (PLA), polyethylene terephthalate glycol (PETG), acrylonitrile styrene acrylate (ASA), and thermoplastic elastomer (TPE) as filament feedstocks for the validation. The 3D-printed connectors underwent hydrostatic water pressure tests to meet standards for residential, agricultural, and renewable energy production applications. All the printed parts passed numerous hydrostatic pressure tests. PETG couplings can tolerate up to 660±20 psi of hydrostatic pressure, which is eight times larger than the highest standard water pressure for the residential sector. Based on the economic analysis, the cost of 3D printing a pipe coupling is 3 to 17 times lower cost than purchasing a commercially available pipe fitting of a similar size. The new open-source couplings demonstrate particular potential for use in developing countries and remote areas.