Abstract: A sealing arrangement for a centrifugal pump is provided. The sealing arrangement permits a sealing gap between a rotating element such as a pump impeller and a non-rotating element such as a pump casing to be minimized, while protecting against element wear from gap reduction and element contact, particularly during transient operation such as pump start up. At least one of the rotating element and the non-rotating element is provided with a plurality of movably mounted bodies configured to rotate and maintain separate the rotating and non-rotating elements when the sealing gap is reduced. The elements and the bodies may be formed in an additive manufacturing process.

Abstract: A method for producing components from a duplex steel, and a component formed by the method, are provided. A powder-type duplex steel starting material including an austenitic phase and a ferritic phase is laser melted in successive layers to form a component. The melted and re-solidified component is then subjected to heat treatment to obtain solution annealing of the austenitic phase at a temperature range of between 850° C. and 1,100° C. for a predetermined dwell time, after which the component is cooled and the component has a grain size and grain size number G of at least 9 according to ASTM. The grain size and the grain size number G of the austenitic phase are influenced by the selection of the respective maximum temperature and/or the dwell time of the maximum temperature.

Abstract: A sealing arrangement for a centrifugal pump is provided. The sealing arrangement permits a sealing gap between a rotating element such as a pump impeller and a non-rotating element such as a pump casing to be minimized, while protecting against element wear from gap reduction and element contact, particularly during transient operation such as pump start up. At least one of the rotating element and the non-rotating element is provided with a plurality of movably mounted bodies configured to rotate and maintain separate the rotating and non-rotating elements when the sealing gap is reduced. The elements and the bodies may be formed in an additive manufacturing process.

Abstract: A method for producing components from a duplex steel, and a component formed by the method, are provided. A powder-type duplex steel starting material including an austenitic phase and a ferritic phase is laser melted in successive layers to form a component. The melted and re-solidified component is then subjected to heat treatment to obtain solution annealing of the austenitic phase at a temperature range of between 850° C. and 1,100° C. for a predetermined dwell time, after which the component is cooled and the component has a grain size and grain size number G of at least 9 according to ASTM. The grain size and the grain size number G of the austenitic phase are influenced by the selection of the respective maximum temperature and/or the dwell time of the maximum temperature.