Pump liner

A pump liner for a centrifugal pump, wherein the pump liner comprises:

• a main pumping chamber having an inner peripheral surface portion;
• an inlet to the main pumping chamber;
• a transition zone;
• and
• a discharge outlet having an inner peripheral surface portion and extending from the transition zone,
• wherein the transition zone includes a transition surface between the inner peripheral surface portion of the pumping chamber and the inner peripheral surface portion of the discharge outlet,
• wherein the pump liner is formed from at least two elastomeric compounds including a first compound and a second compound,
• wherein the first compound has a greater hardness than the second compound,
• wherein the second compound is provided in at least 50% of the transition zone,
• wherein the pump liner has a main region and an exit region, the main region encompassing at least a portion of the main pumping chamber,
• wherein the main region is formed from the first compound that has the greater hardness than the second compound,
• wherein the exit region includes the transition zone and at least part of the discharge outlet, and
• wherein the exit region is substantially formed from the second compound.

A method of producing a side part of a pump liner for a centrifugal pump, wherein the pump liner comprises a main pumping chamber having an inner peripheral surface portion, an inlet to the main pumping chamber, a transition zone, and a discharge outlet positioned adjacent to the transition zone and having an inner peripheral surface portion the transition zone comprising a transition surface between the inner peripheral surface portion of the pumping chamber and the inner peripheral surface portion of the discharge outlet, the pump liner comprising two side parts which can be fitted together in use wherein each of said side parts comprises a part of the main pumping chamber and the discharge outlet, wherein the pump liner is formed from at least two elastomeric compounds including a first compound and a second compound, the first compound having a greater hardness than the second compound, wherein at least 50% of the transition zone is composed of the second compound, wherein the pump liner has a main region and an exit region, the main region encompassing at least a substantial portion of the main pumping chamber and formed from the first compound, wherein the exit region includes the transition zone and at least part of the discharge outlet, wherein the exit region is substantially formed from the second compound, the method including the following steps:

• a) providing a mould that corresponds to one of the said side parts;
• b) positioning the first compound and the second compound in the mould;
• c) compressing the first compound and second compound at an elevated temperature into the mould to produce a moulded side part for a pump liner;
• and,
• d) allowing the moulded side part to cure.