Split Casing Pump Guide

17 Nov.,2022


What is a split casing pump?

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. 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.

Units typically have inline suction and discharge and are designed to produce high flows at relatively low pressures <200M. The top part of the casing when removed allows for ease of pump maintenance as parts slot neatly within the pump casing and can be accessed very easily.

Split casing Pumps can be either vertical or horizontal in execution. Due to the size of such pumps, they are generally easier to maintain when the units are horizontal in design, as the motor does not need removing to maintain the pump.

What is a radially split casing pump?

Radially split casing pumps are quite different in that a pump has its casing opening across or perpendicular to the shaft. They are usually of back pull out design meaning for maintenance to take place a motor must be disconnected, then parts pulled out of the pump


Typical applications include:

-          Firefighting

-          Water deluge

-          Oil and Water Supply through pipelines

-          Ballast

-          Cooling


                                                      Spilt Casing vs End Suction Pump

Can not   accommodate solids – single impeller type

Impeller can be changed to vortex, channel, chopper, open or closed according to requirement

Flows of up to 6000M³H achievable

Limited to <2000M³H

Lower NPSH and axial thrust due to double volute

Wear rings can wear unevenly creating vibration

Single impeller less susceptible to vibration caused by unbalanced wear on wear rings

Non Self Priming but can achieve manometric suction lift with footvalve

Can be made self priming with external vacuum pump

Double the spare parts increases stock holding and cost of maintenance.

Less stock holding required

Standard Sealing Methods

Larger range of shaft seal types available to accommodate fluid types

Larger Footprint


View our range of pipeline pumps. 

Having trouble with your split casing pump? View our troubleshooting guide.