Vacuum distillation separates the residue from the atmospheric crude into a heavy residual oil and one or more heavy gas oil streams, thereby avoiding the extremely high temperatures necessary to produce these heavy distillates by atmospheric fractionation through operation at a reduced pressure (approximately 15-50 mm Hg absolute pressure). Atmospheric residue is heated in a direct-fired furnace and fed to the vacuum fractionator at 400ºC to 425ºC. The intermediate products from the vacuum distillation process are sent to hydrotreating, hydrocracking or a catalytic cracking unit.