Abstract: A pump unit for a nuclear installation, for example a pressurized water reactor, contains a vertical shaft, which is guided through at least one journal bearing. The journal bearing or bearings is or are configured as a spiral groove bearing or bearings, to prevent shaft vibration caused by the bearings and to increase the service life of the pump unit. Preferred uses of the pump units include, for example, the coolant pump of a pressurized water reactor and the circulating pump of a boiling water reactor.

Abstract: Self-driven vehicle for pipelines comprising: a cylindrically designed vehicle body (1) through which and/or around which the pipeline's (10) medium flows, a drive unit (2) on the vehicle body (1) which resiliently bears against the pipeline's (10) internal surface, a hydraulic system which powers the drive module (2), a power supply system for operation of the hydraulic system, and a controller (22) which at least controls the vehicle's movement in the pipeline (10).

Abstract: A rotating piston compressor includes a cylinder having inlet and outlet openings formed therein, a piston rotating in a given direction in the cylinder, a shaft supporting the piston and rotating in the given direction, a casing connected to the cylinder and having slits formed therein, a control device for controlling flow through the inlet and outlet openings in the form of a rotary slide disposed outside the cylinder in the casing, the rotary slide being connected to the shaft for a steady, synchronized rotational movement, and the relative position of the rotary slide and the casing being adjustable.

Abstract: A shutoff valve, includes a conical valve seat, and a valve disc movable toward the valve seat in a given direction, the valve disc including a base body covering the valve seat, an annular projection projecting from the base body in the given direction, and a rim formed on the outside of the projection resting against the valve seat in a closed position of the valve, the projection having a region with a given wall thickness in vicinity of the base body and the projection having a free end reinforced to at least 1.5 times the given thickness in the radial direction.