There are three typical problems encountered in pipe flows: unknown friction factor, unknown flow rate, and unknown diameter problems. A major problem in determining the solution to these flow problems occurs due to the implicit nature of the Darcy-Weisbach friction factor. Though explicit equations for flow of Newtonian fluids and Power Law fluids are available, no such usable equations exist for Herschel-Bulkley fluids. In this paper, explicit equations have been given for flow of Herschel-Bulkley fluids in the laminar regime.