A. Solid Dense Phase : Very low material velocity - pipeline full of material-an excellent regime for fragile materials.
B. Discontinuous Dense Phase :- Low material velocity - pipeline almost full of material which moves in plug flow fashion-best regime for most applications in which power economy. pipe erosion and material degradation issues are important.
C. Continuous Dense Phase :- Highest velocity below the saltation velocity of the material conveyed-suitable for powder and narrow particle size distribution may not be optimum design for abrasive materials.
D. Dilute Phase :- Material Velocity above the saltation velocity - no upper limit to the velocity least attractive regime for operating economy-unsuitable for abrasive materials or materials with wide particle size distribution.