A fuel injector includes a valve stack forming a seal cavity, and an outlet check extending through the seal cavity. A check seal is positioned within the seal cavity and seals about the outlet check. The valve stack also includes a back-up plate trapping the check seal within the seal cavity, such that a crevice is formed within the seal cavity between the check seal and the back-up plate. The back-up plate has a vent formed therein that fluidly connects the crevice to a drain.

Provided is a steel fuel conveying pipe with high quality which has high resistance to corrosive fuel and followability, and allows working after plating. The steel fuel conveying pipe is characterized in that a Ni-plate layer is formed on an inner surface of a steel pipe of base material, the Ni-plated layer is wholly composed of a mutual diffusion layer including the base material and Ni and a non-mutual diffusion layer including only Ni formed on an outermost surface of the diffusion layer, a layer thickness of the non-mutual diffusion layer is 3 m or more, and a total layer thickness of the mutual diffusion layer and the non-mutual diffusion layer is 10 m or more and 25 m or less.

An assembly at least comprising a fuel injector for dual fuel operation of an internal combustion engine. The assembly includes a nozzle holder defining a fuel circuit and provided with a nose adapted in use to be in connection with a combustion space of an internal combustion engine, and first and second nozzles in communication with the fuel circuit in the nozzle holder for directly injecting liquid fuel into the combustion space of the internal combustion engine for ignition of a combustible mixture present in the combustion space. The first and second nozzles adjacent to the nose of the nozzle holder are interconnected by a cooling channel. At each actuation of a fuel pump upstream of the first and second nozzles, substantially a full volume of fuel pumped during actuation of the fuel pump is allowed to flow through the cooling channel and via the first and second nozzles.

A large two-stroke turbocharged compression-ignited internal combustion crosshead engine with a plurality of cylinders has at least one pressure booster for each cylinder for boosting fuel pressure, two or more electronically controlled fuel valves for each cylinder with an inlet of the two or more electronically controlled fuel valves being connected to an outlet of the at least one pressure booster. An electronic control unit is connected to the at least one pressure booster and the two or more electronically controlled fuel valves. The electronic control unit is configured to determine a start time for a fuel injection event, activate the at least one pressure booster ahead of the determined start time and pen the two or more electronically controlled fuel valves at the determined start time.

A large two-stroke turbocharged compression-ignited internal combustion crosshead engine with a plurality of cylinders has at least one pressure booster for each cylinder for boosting fuel pressure, two or more electronically controlled fuel valves for each cylinder with an inlet of the two or more electronically controlled fuel valves being connected to an outlet of the at least one pressure booster. An electronic control unit is connected to the at least one pressure booster and the two or more electronically controlled fuel valves. The electronic control unit is configured to determine a start time for a fuel injection event, activate the at least one pressure booster ahead of the determined start time and pen the two or more electronically controlled fuel valves at the determined start time.

A fuel pipe includes a tubular header pipe and a socket coupled to the header pipe and supplied with fuel from the header pipe. The header pipe and the socket form a joining portion therebetween. The joining portion is shaped to be elongated in a first direction. The joining portion includes a communication hole that connects an inner region of the header pipe and an inner region of the socket. The communication hole is an elongated hole elongated in the first direction.

A valve for metering highly pressurized fluid, having an inlet connector that can be placed into a connection socket of a fluid supply line, and a sealing assembly situated on the inlet connector, the sealing assembly having an elastically deformable sealing ring and a support ring made of plastic, which sealing assembly is supported on a radial support shoulder present on the inlet connector and seals against the connection socket. To prevent radial gaps between the support ring on the one hand and the inlet connector and/or the connection socket on the other hand, into which gaps the sealing ring extrudes under high pressure and becomes damaged, the support ring situated between the sealing ring and the support shoulder is made of an elastically deformable plastic material.

A quick fit connector is disclosed for the return line of fuel injectors in an internal combustion engine. The connector includes a T- or L-shaped connector body having at least one connection branch insertable in a fuel return port of a fuel injector, a lower plate, an upper plate and a spring clip. The upper plate is slidingly mounted on the spring clip and the connector body and is movable between an unlocked position, in which the spring clip is in unloaded condition and free from any engagement with the fuel injector, and a locked position in which the spring clip is in loaded condition and engages the fuel injector and the lower plate.

A sealing structure includes an O-ring and a back-up ring. An outer diameter of the back-up ring is smaller than an inner diameter of a mounting portion of a delivery pipe. An inner diameter of the back-up ring is gradually increased from a pressure-receiving surface toward a seating surface, and is greater than an outer diameter of a fuel introducing portion of a fuel injection valve. In a section of the back-up ring, an edge angle defined between the pressure-receiving surface and an inner circumferential surface is smaller than a gap angle defined between the pressure-receiving surface and a tapered outer surface of a tapered portion in the fuel introducing portion. A dimension of the seating surface in the back-up ring is shorter than a dimension in an end surface.

A sealing device has a seal ring, a first backup ring and a second backup ring. The first backup ring is formed into a triangular cross section while having an axially vertical end surface portion, a cylindrical peripheral surface portion, and an inclined surface portion intersecting the end surface portion and the peripheral surface portion. The second backup ring is formed into a triangular cross section while having an axially vertical end surface portion, a cylindrical peripheral surface portion, and an inclined surface portion in correspondence to the inclined surface portion of the first backup ring. A cut portion is provided in a corner portion where the end surface portion and the inclined surface portion in the first backup ring intersect, and a corner portion where the peripheral surface portion and the inclined surface portion in the second backup ring intersect.