pump casing

what do you want to know exactly? Pump cases are used to aid in the conversion of kinetic energy of a fluid to pressure head, which allows a pressure gradient to form, thus fluid flow occurs. Also I guess, if the interworkings of the impeller were not shielded you would have a mess on your hands!

what is that you want to know about the pump casing?

When liquid enters the Pump Inlet and as it passes through Impeller Eye and into the Impeller passages formed by vanes, the rotation of Impeller generates Kinetic Energy (KE) in liquid. It is then passes through the pump casing, where this Kinetic Energy is converted into Pressure Energy, which is known as Pump Head.

In a simpler pump having casing, is generally known as Volute. This Volute is having a progresively increasing flow areas, at the outlet of Impeller periphery, where the outgoing liquid from the impeller is collected and as the liquid passes through volute, conversion of KE into Pressure Energy takes place, in a smoother and gradual manner. Finally, the liquid is discharged from the casing outlet, into piping system connected with the pump.