Abstract: A thermal barrier which is interposed between the casing of a pump and the housing of a motor has a first section which resembles a spool and includes a first flange sealingly connected to the casing, a second flange sealingly connected to the housing and a hollow cylindrical core spacedly surrounding the pump shaft between the two flanges. The first section serves primarily or exclusively to establish a seal between the pump casing and the motor housing, and the thermal barrier has a second section which takes up stresses and further serves as a heat insulating and/or heat dissipating device. The second section is removably installed in the space between the two flanges of the first section and spacedly surrounds the core. The second section may be constituted by hollow cylindrical walls, one or more stacks of washers or rings, one or more annuli of parallel tubes, bars, rods, ribs or a combination of such elements.

Abstract: A centrifugal pump has a casing with a cylindrical shell surrounding a volute-type inner section which is formed with a hollow radial extension for admission of fluid into a nipple of the shell. The extension forms part of or constitutes a separable sealing device between a passage of the inner section and a passage of the shell. The inner section is suspended in the shell by one or more pipes which are coaxial with the rotor and/or by one or more projections which extend radially from the inner section and abut against the internal surface of the shell or extend into recesses provided therefor in the internal surface of the shell.

Abstract: The casing of a centrifugal pump which is subjected to pronounced external stresses is secured to a foundation or to a base plate by one or more rings which surround the casing and receive stresses therefrom. Each ring has lugs which transmit the stresses to the support; one surface of each such lug can be located in a plane which includes the axis of the pump casing and each of these surfaces abuts a complementary surface of the support. If the casing is surrounded by two rings, each ring is located at a different axial end of the casing. One of the rings can be shrunk onto the casing, and the other ring then allows the casing to move angularly and/or axially therein or therewith but relative to the foundation or base plate so as to compensate for dimensional changes in response to temperature changes. Instead of being shrunk onto the casing, the one ring can be secured thereto by one or more keys, wedges and/or pins.

Abstract: The casing of a centrifugal pump has a shell with a cylindrical periphery having one or more recessed facets with flat or spherical surfaces which are welded to end portions of pipes by circumferentially complete machine-made seams each of which is intersected, in its entirety, by at least one imaginary plane that is normal to the axis of the respective pipe. This renders it possible to use automatic welding equipment and to readily inspect the quality of the connection between the shell and a pipe. The surface of the facet can be formed with a circumferentially complete groove to receive a transducer serving to generate signals denoting the intensity of penetrative radiation which has penetrated through the seam from a source of such radiation in the interior of the respective pipe and in register with the respective seam. The shell is suspended on the arms of a foundation and such arms extend into additional facets which are recessed into the periphery of the shell.

Abstract: An apparatus which removes contaminants from the liquid in a centrifugal pump has a housing connected with the pump shaft and having a cleaning chamber connected with a first space containing contaminated liquid and a second chamber connected with a second space for cleaned liquid as well as with the first chamber. The second space communicates with the first space by way of a narrow clearance which further communicates with an outlet of the first chamber. The first chamber can contain a disc separator and its outlet is positioned in such a way that, when the housing rotates, liquid entering the first chamber from the first space is relieved of impurities and flows into the second chamber where it can undergo additional cleaning prior to entering the second space. The contaminants return into the first space via outlet and the clearance, and those contaminants which are contained in the liquid entering the second space are returned into the first space by way of the aforementioned clearance.

Abstract: The housing of the primary recirculating pump in a nuclear reactor plant has a reinforced annular portion at the inlet and/or outlet and anchoring means provided on the annular portion and on the foundation to allow for limited movement of the housing relative to the foundation in response to development of major stresses which are likely to arise in the event of breakage of one or more pipes or as a result of earth tremors. The inertia of the annular portion or portions in response to temperature changes can be reduced by forming their end faces with one or more circumferentially complete grooves which surround the adjacent ends of the respective pipes. The anchoring means may comprise cylindrical pins which extend radially from the respective annular portion and into complementary sockets provided on clamps, claws or analogous anchoring parts in or on the foundation.

Abstract: A flexible shaft coupling wherein the flange of at least one of the shafts is flexible and its marginal portion is separably fastened to the marginal portion of the other flange. The flanges surround thrust transmitting elements which are urged against each other as a result of deformation of the flexible flange in response to fastening to the other flange. The flexible flange may be integral with or it may be separably fastened to the shank of the respective shaft. The flexibility of the coupling is enhanced if the flexible flange is provided with or mounted between knife edges which permit such flange to snap over in response to tilting of one shaft with respect to the other shaft and/or vice versa. The thrust transmitting elements may be integral with the respective shafts or they may constitute removable inserts. One of the thrust transmitting elements has a convex face which bears against a flat face of the other element so that the elements are in mere point contact with each other.