Basically its a type of centrifugal pump, in which the casing is split into two separate chambers. It’s different from an end suction pump or inline pump, in which the casing, the suction nozzle, and the discharge nozzle are all included in a single chamber. When the casing is split along a vertical plane in relation to the impeller, it’s known as a vertical split case pump; when it’s on a horizontal plane, it’s known as a horizontal split case pump.
This type of casing design is more economical for higher flow applications, and the impeller can be supported by bearings on both sides, an advantage for larger, higher flow pumps. The pump has the suction and discharge connections in the lower half of the casing, opposed to each other. The impeller is mounted on a shaft which is supported by bearings on both sides.