There are two types of performance curves that characterize the Discflo pump. The first is a steep sloping H-Q curve which applies to the original smooth Discpac design (Fig 1.5). The second is a flatter H-Q curve, which applies to the second generation, "high head" Dispac design (Fig 1.6). The high head design was developed in 1988. It incorporates a number of straight radial or curved ribs on the inside (opposing) surfaces of multiple disc configurations. This design has been shown to produce much higher flow rates and discharge pressures than comparably sized smooth disc designs, so the user can select a smaller pump and lower horsepower motor.

The ribbed design can be compared to a corrugated pipe. The corrugations or ribs increase friction and hence increase efficiency, without disturbing the laminar flow. Another way to think of it is that the ribs effectively increase the thickness of the boundary layer, so not only does the "non-impingement" principle still apply but it is also reinforced by having a thicker, more protective buffer between the fluid particles and the discs.

Note: The performance curves for the Discflo pumps are generally flatter than those of competitive pumps. This means the pump is sensitive to changes in head, and a high degree of accuracy is required when specifying flow conditions. In other words, small variations in head will cause wide variations in performance.

Note: Performance curves are based on the Discflo pump's performance when pumping water. A correction factor must be applied to calculate the correct flow rate, head and horsepower when pumping more viscous fluids. See General Definitions for viscosity correction factors.