Vertical centrifugal pumps are also referred to as cantilever pumps.
They utilize a unique shaft and bearing support configuration that allows the volute to hang in the sump while the bearings are outside of the sump. This style of pump uses no stuffing box to seal the shaft but instead utilizes a "throttle Bushing".
A common application for this style of pump is in a parts washer.
Vertical pump provides benefits of low installation costs and space savings...without compromising reliability, maintainability, safety or hydraulic performance.
The only difference between horizontal and vertical centrifugal pumps is shape. The choice between using a horizontal centrifugal pump or a vertical centrifugal pump is usually based on convenience.