A split casing pump is a type of pump whereby the casing is split either perpendicular or radially across the shaft to allow easy access to internal pump parts for maintenance.

The term is widely used to refer to a double suction pump / pipeline pump where an impeller which is designed for producing high volume flows of potable and raw water without the prescence of solids. This is due to the impeller being of back to back design, where its design is like two impellers mounted together, mounted within a double volute.

Split casing pump designs have a single double impeller mounted on a shaft, with twin wear rings, twin mechanical seals or packing box, twin bearings and double volute. Such units are known to be highly efficient and consequently used in pipelines both for water and oil where pumps operate 24/7 transferring high amounts across large distances. These are known as axially split pumps.