Under the assumption of a vanishingly small pressure and a small viscosity accretion disk in a close binary system, gas streamlines are calculated via an approximate analytical method in the framework of the restricted three body problem. An outer limit for the disk is found, defined by the last non-intersecting orbit, in agreement with previous works. Once the velocity field is determined, a series of line profiles are numerically computed, under the assumption of a r-α emissivity law, for different orbital phases and for a range of mass ratios.