Abstract: A double suction impeller is disclosed. In at least one embodiment, the impeller is configured for centrifugal pumps and hydraulic power recovery turbines. The impeller's flow-path arrangement comprises inter-blade channels, intersecting each other at the impeller's outer diameter and defining a variable cross section shape, so that the equivalent number of blades is at least doubled with respect to a conventional configuration obtained by the coupling of two single suction impellers and an improved control over the velocity of the flow within the inter-blade channels is achieved.

Abstract: A system and modular compressor for raising the pressure in production gas is disclosed, wherein in a set of compressor modules each second module is a rotor module carrying an impeller driven in rotation relative to an adjacent stationary module, a rotor module and a stationary module in combination providing a compressor stage in which production gas is accelerated through a flow duct that passes an interface between the rotor module and the stationary module, wherein at the interface at least one bearing for axial and/or radial load is provided for journaling the rotor module on the stationary module. The at least one bearing is a gas bearing, wherein a passage is arranged in the stationary module to lead an extracted portion of production gas at raised pressure from the compressor to the gas bearing(s).

Abstract: A double suction impeller is disclosed. In at least one embodiment, the impeller is configured for centrifugal pumps and hydraulic power recovery turbines. The impeller's flow-path arrangement comprises inter-blade channels, intersecting each other at the impeller's outer diameter and defining a variable cross section shape, so that the equivalent number of blades is at least doubled with respect to a conventional configuration obtained by the coupling of two single suction impellers and an improved control over the velocity of the flow within the inter-blade channels is achieved.

Abstract: A seal for a gap between an outer and an inner cylindrical surface, coaxial with a central axis in common and arranged to rotate reciprocally, the seal comprises a plurality of plate elements stacked onto one another to define a ring between the outer and inner cylindrical surfaces, wherein each plate has a concave and a convex side, the convex side of each plate element being adjacent to the concave side of the next plate element.

Abstract: A double suction impeller is disclosed. In at least one embodiment, the impeller is configured for centrifugal pumps and hydraulic power recovery turbines. The impeller's flow-path arrangement comprises inter-blade channels, intersecting each other at the impeller's outer diameter and defining a variable cross section shape, so that the equivalent number of blades is at least doubled with respect to a conventional configuration obtained by the coupling of two single suction impellers and an improved control over the velocity of the flow within the inter-blade channels is achieved.

Abstract: A seal assembly for a piston rod including an external seal and an internal seal. The external seal is adapted to be placed on a piston rod facing an external environment, the internal seal is adapted to be placed on the rod facing the cylinder associated to the piston. The external and internal seals define in cooperation with each other a chamber for the containment of barrier fluid. Such chamber has an inlet for the intake of barrier fluid and an outlet for the exit of barrier fluid. The assembly also comprises a recirculation circuit for the barrier fluid, which is placed in fluid communication with the inlet and the outlet to recirculate the barrier fluid from the outlet back to the inlet and a pressurizer device configured to be installed coaxially with the piston rod providing the chamber with a positive pressure with respect to the process environment.

Abstract: A turbo machine comprising a barrel casing having a cylindrical internal surface defining an internal containment volume, a bundle having a cylindrical shape, adapted to be accommodated into the internal containment volume, a cylindrical cover connected to the bundle to close the internal containment volume and hold the bundle inside the barrel casing, a split shear ring adapted to fix the barrel casing with the cylindrical cover wherein the external cylindrical surface of the cylindrical cover and the cylindrical internal surface of the barrel casing are provided with a first circumferential groove and a second circumferential groove adapted to accommodate the shear ring and wherein the first grooves is adapted to completely accommodate the cross section of the split shear ring.

Abstract: A double suction impeller is disclosed. In at least one embodiment, the impeller is configured for centrifugal pumps and hydraulic power recovery turbines. The impeller's flow-path arrangement comprises inter-blade channels, intersecting each other at the impeller's outer diameter and defining a variable cross section shape, so that the equivalent number of blades is at least doubled with respect to a conventional configuration obtained by the coupling of two single suction impellers and an improved control over the velocity of the flow within the inter-blade channels is achieved.

Abstract: A seal assembly for a valve stem comprises an external seal placed on a valve stem facing an external environment; an internal seal placed on the valve stem facing a process environment; the external and internal seals define a chamber for the containment of barrier fluid; the chamber has an inlet configured to be placed into fluid communication with a source of barrier fluid; a detector of the amount of barrier fluid; a pressurizer device for providing the chamber with a positive pressure with respect to the process environment; the pressurizer device is configured to be installed coaxially with the valve stem.

Abstract: A multistage turbomachine is disclosed, comprising a casing with a fluid inlet and a fluid outlet and a plurality of stages arranged in the casing. A flow path extends from the fluid inlet to the fluid outlet through the sequentially arranged stages. Each stage is comprised of a rotating impeller and an electric motor embedded in the casing and arranged for rotating the impeller at a controlled rotary speed. Each electric motor comprises a motor rotor, arranged on the impeller and integrally rotating therewith, and a motor stator stationarily arranged in the casing. Pairs of sequentially arranged impellers are configured for rotation in opposite directions.

Abstract: A system and modular compressor for raising the pressure in production gas is disclosed, wherein in a set of compressor modules each second module is a rotor module carrying an impeller driven in rotation relative to an adjacent stationary module, a rotor module and a stationary module in combination providing a compressor stage in which production gas is accelerated through a flow duct that passes an interface between the rotor module and the stationary module, wherein at the interface at least one bearing for axial and/or radial load is provided for journaling the rotor module on the stationary module. The at least one bearing is a gas bearing, wherein a passage is arranged in the stationary module to lead an extracted portion of production gas at raised pressure from the compressor to the gas bearing(s).

Abstract: A new double suction impeller, in particular for centrifugal pumps and hydraulic power recovery turbines, wherein the flow-path arrangement has inter-blade channels intersecting each other at the impeller's outer diameter so that the equivalent number of blades is doubled with respect to a conventional configuration obtained by the coupling of two single suction impellers.

Abstract: A seal assembly for a piston rod including an external seal and an internal seal. The external seal is adapted to be placed on a piston rod facing an external environment, the internal seal is adapted to be placed on the rod facing the cylinder associated to the piston. The external and internal seals define in cooperation with each other a chamber for the containment of barrier fluid. Such chamber has an inlet for the intake of barrier fluid and an outlet for the exit of barrier fluid. The assembly also comprises a recirculation circuit for the barrier fluid, which is placed in fluid communication with the inlet and the outlet to recirculate the barrier fluid from the outlet back to the inlet and a pressurizer device configured to be installed coaxially with the piston rod providing the chamber with a positive pressure with respect to the process environment.

Abstract: A control valve comprising a cylindrical hollow trim defining an inner bore extending along an axis between a first opening and a second opening, the first opening defining an inlet of the valve, the trim comprising a first outer cylinder extending along the axis and comprising a first plurality of radial through holes defining an outlet, a second cylinder, housed in the first cylinder and coaxial, the second cylinder comprising a second plurality of radial through holes, the holes of the first plurality being smaller and in greater number than the holes of the second plurality, for each hole of one of the first and second cylinders the projection along a radial direction on the other of the first and second cylinders being spaced from each hole of the other of the first and second plurality a plug sized to fit inside the bore and slidably movable along the axis.

Abstract: A back-to-back centrifugal pump comprising a pump inlet, a pump outlet, a pump shaft, a set of first stages, and a set of second stages in a back-to-back arrangement. Between the two sets of stages an intermediate crossover module is arranged. The first and second sets of stages comprise respective first outer diaphragms and second outer diaphragms. The outer diaphragms and the intermediate crossover module are stacked together and form a pump casing. The intermediate crossover module forms at least one axial transfer channel between the two sets of stages, and a fluid connection between the set of second stages and the pump outlet. The second diaphragms comprise each at least one peripherally arranged through aperture. The through apertures are aligned to form at least one passageway, which fluidly connects the axial transfer channel with a most upstream one of the impellers of the second set of stages.

Abstract: A seal for a gap between an outer and an inner cylindrical surface, coaxial with a central axis in common and arranged to rotate reciprocally, the seal comprises a plurality of plate elements stacked onto one another to define a ring between the outer and inner cylindrical surfaces, wherein each plate has a concave and a convex side, the convex side of each plate element being adjacent to the concave side of the next plate element.

Abstract: A seal assembly for a valve stem comprises an external seal placed on a valve stem facing an external environment; an internal seal placed on the valve stem facing a process environment; the external and internal seals define a chamber for the containment of barrier fluid; the chamber has an inlet configured to be placed into fluid communication with a source of barrier fluid; a detector of the amount of barrier fluid; a pressurizer device for providing the chamber with a positive pressure with respect to the process environment; the pressurizer device is configured to be installed coaxially with the valve stem.

Abstract: A multistage turbomachine is disclosed, comprising a casing with a fluid inlet and a fluid outlet and a plurality of stages arranged in the casing. A flow path extends from the fluid inlet to the fluid outlet through the sequentially arranged stages. Each stage is comprised of a rotating impeller and an electric motor embedded in the casing and arranged for rotating the impeller at a controlled rotary speed. Each electric motor comprises a motor rotor, arranged on the impeller and integrally rotating therewith, and a motor stator stationarily arranged in the casing. Pairs of sequentially arranged impellers are configured for rotation in opposite directions.

Abstract: A valve comprising a valve body with a fluid inlet, a fluid outlet, an inner cavity and an outer cavity at least partly surrounding the inner cavity. The outer cavity is in fluid communication with the fluid inlet and with the inner cavity and the inner cavity is in fluid communication with the fluid outlet. A flow splitter is provided, forming at least two flow passages in the outer cavity.

Abstract: A method for supplying barrier fluid in a subsea motor and pump assembly is disclosed, wherein desalinated water is extracted from or downstream of a reverse osmosis device and supplied to the motor and pump assembly, alone or as mixture with ethylene glycol. A corresponding system is likewise disclosed.