Operations related to the production of poultry can generate effluents from different sources, including the runoff resulting from the cages, food and water for birds and storage facilities and waste management. In any proposed poultry farm, one must take into account the handling of waste and wastewater, which can be channeled in galvanized iron pipes. The aim of this study the equations to estimate continuous head loss in galvanized iron pipelines in the commercial diameters varying from 50 to 150 mm, when in operating with laying hen wastewater in different concentrations of total solids. The results indicated that the methodologies of Duffy & Titchener and Hazen-Williams modified gave results with coefficient of determination superiors to 0.95.