Patent ID: 8240976

Claim:
In a centrifugal pump housing including a rotatable impeller having radial blades and an axial diffuser having vanes angularly spaced downstream of said impeller by a cross-overgap formed within said pump housing so that the fluid subjected to the impeller must move through said cross-over gap to be driven into said axial diffuser, the improvement comprising at least a single, axial diffuser vane extension mounted circumferentially with said axial diffuser and extending into said cross-over gap for guiding the fluid flow from said impeller through the cross-over gap and driven to said axial diffuser, said diffuser vane extension being constructed designed and formed in structure with a tandem vane portion for imparting a twisting force to the fluid received from said impeller for minimizing any turbulence present in the fluid stream as it leaves the impeller whereby said pump exhibits a pump head curve that has been modified for eliminating flat or positive slopes as the flow-head curve becomes continuously rising toward shut-off.