In this paper, the particle suspension flows in pipes are classified into three major regimes of: flow with a stationary particle bed, flow with moving particle bed or dunes, and flow of fully dispersed particle-liquid mixture. It is shown that these regimes can be characterized by only two dimensionless parameters, which are the ratios of the characteristic flow velocity and particle shear velocity, and projection of the particle settling velocity on the direction of the flow. The dimensionless flow regime maps for both circular pipe flow and annulus flow are built using available experimental data and applicable to a wide range of flow parameters. In the considered experiments, the size of the solid particles varied from several micrometers to 1 cm, the particles fraction varied from less than 1% to approximately 40%, and the solid phase was formed by different particles, such as glass spheres (1.24 sg) and sand (2.5 to 3.0 sg). The inclination angle of the flow changed from 0 to 180°. A methodology using suggested mapping for pipe and annulus flow calculations is described in detail.