The present invention relates to a system for distributing electrical energy, comprising an electricity grid configured to supply electrical energy to end users, characterized in that the grid is operated on a direct voltage.

Methods and electric circuit arrangements for protecting metallic components in an electrolytic medium from corrosion due to direct-current (DC) stray current (Is) from a power supply system. The DC stray current may be jointly registered as a total sum current across all active conductors together with the protective conductor of the power supply system by a DC total differential-current sensor. Alternatively, a combined DC differential-current sensor is switchable by a switching device, a differential current being registered across all active conductors or the DC stray current being registered as a total differential current across all active conductors and the protective conductor. Alternatively, a differential current may be registered across all active conductors by a DC current sensor at the protective conductor and the DC stray current computed by forming differences of the differential current registered by the differential-current transformer and of the protective conductor registered by the DC current sensor.

A main object of the present disclosure is to provide a fuel cell system capable of inhibiting corrosion of components due to a stray current in a structure of connecting a plurality of fuel cells in series. The present disclosure achieves the object by providing a fuel cell system including a fuel cell, a coolant circuit that circulates a cooling liquid to cool the fuel cell; wherein the fuel cell system includes: as the fuel cell, at least a first fuel cell and a second fuel cell; and as the coolant circuit, at least a first coolant circuit that cools the first fuel cell, and a second coolant circuit that cools the second fuel cell; and the first fuel cell and the second fuel cell are connected in series in a manner the first fuel cell is in a low potential side and the second fuel cell is in a high potential side; the first coolant circuit and the second coolant circuit are respectively connected to a grounding member interposing a first connecting member and a second connecting member; the first coolant circuit includes a sacrifice corrosion member; and the sacrifice corrosion member contacts the first connecting member.

The present invention relates to a system for distributing electrical energy, comprising an electricity grid configured to supply electrical energy to end users, characterized in that the grid is operated on a direct voltage.

An isolating flow line spool fitting, particularly for electrical isolation of above-ground steel flow lines or other pipes. Two opposing half segments are electrically separated from each other by non-conductive isolating materials. A first half segment includes a threaded male connection member, while a second half segment includes a mating threaded collar for threadedly connecting the second half segment to the first half segment, and thereby forming a fluid pressure seal.

A mechanical joint and method for controlling stray current in a buried or submerged pipeline made of ductile iron, cast iron and/or steel that includes a gasket arrangement having an annular gasket body with a radially inward and outward edge portions and first and second longitudinal edge portions, the radially outward edge portion and the radially inner edge portion being generally coaxial with a gasket axis, the radially inner edge portion having an inner engagement surface and the radially outer edge portion having an outer engagement surface, when in an installed condition, the outer surface directly engaging a first pipe and the inner engagement surface directly engaging a second pipe wherein the gasket forms a seal between the first and second pipes, the annular gasket includes an intrinsically conductive polymer material having a resistivity below 700 ohm-cm wherein the gasket provides the seal and electrical conductivity between the pipes thereby allowing stray current to freely pass through the polymer material and between the first and second pipes to reduce and/or eliminate corrosion-induced holes.