housing however the similarity is purely aesthetic as both operate in literally different directions though both require sealed impeller chamber housings so as to achieve maximum performance every other aspect is entirely different and serve to function contrasting purposes there are at least three significant points that differentiate the francis from this invention 39 s design concept first the designs operate in opposite flow directions relative to their volute housings two the inlet and discharge size dimensions are opposite that is the inlet is typically larger than the outlet on the francis contrasting the smaller inlet than the outlet that is characteristic of this invention and finally and most significant the impeller designs are very different and neither would work in the other 39 s turbine housing to achieve the same results the francis is in an inward flow design whereas this invention teaches an axi radial flow type disk design that directs flow outwardly from the center rather than tangentially and then in on its self like the francis this invention 39 s turbine incorporates a scrolled discharge section to efficiently manage and release flow as it exits the impeller to sustain velocity whereas the francis uses the scroll to manage inlet flow and directs it around the first runner vanes on its impeller the two designs operate in opposite.