Pump casing

A pump casing for a centrifugal pump having a main pumping chamber, the pump casing comprising:

• an inlet opening arranged for the introduction of a flow of material into the main pumping chamber during use;
• a discharge outlet extending from the main pumping chamber and arranged for the exit of a flow of material from the main pumping chamber during use;
• and
• a transition surface extending between an inner peripheral surface of the main pumping chamber and an inner peripheral surface of the discharge outlet, the transition surface being positioned for separating an in use exit flow of material in the discharge outlet from an in use recirculation flow of material in the main pumping chamber;
• and
• a cutwater formed at the transition surface, when the transition surface is viewed from a line through a central axis of the casing, the line being parallel to a tangential line at the discharge outlet, the cutwater having a profiled section which comprises a removable protrusion connected to the transition surface.