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 flow-conducting component having at least one functional region for contact with a flowing medium and at least one functional region having supporting characteristics is provided. The two functional regions are produced from a material by successively solidifying layers using radiation in a manner that provides different material characteristics in the different functional regions.

Abstract: A flow-conducting component such as a pump impeller is provided. Passages between vanes of the flow-conducting component include notches in the form of transitions between the vane and a common surface, such as a cover disk. The notches include a transition surface having a geometric configuration determined in accordance with a calculated load spectrum along at least a portion of the length of the notch and in accordance with a particular geometric pattern.

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 flow-conducting component having at least one functional region for contact with a flowing medium and at least one functional region having supporting characteristics is provided. The two functional regions are produced from a material by successively solidifying layers using radiation in a manner that provides different material characteristics in the different functional regions.

Abstract: A flow-conducting component such as a pump impeller is provided. Passages between vanes of the flow-conducting component include notches in the form of transitions between the vane and a common surface, such as a cover disk. The notches include a transition surface having a geometric configuration determined in accordance with a calculated load spectrum along at least a portion of the length of the notch and in accordance with a particular geometric pattern.