The subject matter of this specification can be embodied in, among other things, a fuel delivery component, including a substantially rigid, unitary structure formed as a single piece of material, and at least a first seamless lumen defined by the unitary structure.

The invention relates to a pipe having a thermoplastic casing surface a glass-fibre-reinforced thermo-setting coating surrounding the thermoplastic casing surface. The thermo-setting coating is formed from multiple layers of glass-fibre matting or glass-fibre fabric, or a combination of the two, wherein the layers are applied to the thermoplastic casing surface a wet-on-wet method using a vinylester, polyester or epoxy resin. According to the invention, an outer layer of the thermo-setting coating is formed from cross-wound glass-fibre fleece or glass-fibre fabric.

A cross-over fluid coupling includes a first coupling end and a second coupling end. A plurality of first conduits have inner ends disposed toward the first coupling end and outer ends spaced apart from the inner end toward the second coupling end and being outboard of the inner end. A plurality of second conduits have outer ends that are disposed toward the first coupling end and positioned laterally outboard of the inner end of at least one of the first conduits, and inner ends that are spaced apart from the outer end toward the second coupling end in the axial direction and is laterally inboard of the outer end of the at least one of the first conduits.

A double pipe of an embodiment includes: an outer pipe; an inner pipe inserted through an interior of the outer pipe to make high-temperature carbon dioxide flow therethrough; and an opening of the outer pipe which introduces low-temperature carbon dioxide to an annular passage between the outer pipe and the inner pipe. The double pipe further includes: an inner pipe protruding part protruding from an outer peripheral surface of the inner pipe to a radial outside; and an outer pipe protruding part protruding from an inner peripheral surface of the outer pipe to a radial inside, the outer pipe protruding part having a fitting groove fitted to the inner pipe protruding part and penetrating in an axial direction.

A method of installing at sea a double-walled preheated undersea pipe for transporting fluids, wherein for each new pipe section to be assembled to a pipe that is already installed at sea: the method involves preheating the inner wall unit element inside the outer wall unit element of the new pipe section; assembling the inner wall unit elements of the new pipe section to the inner wall of the pipe that is already installed at sea; assembling the outer wall unit element of the new pipe section to the outer wall of the pipe that is already installed at sea; lowering the new pipe section into the sea; and repeating the above for other new pipe sections to be assembled so as to prestress the pipe while it is being installed at sea.

At least two spacers in an elongated shape is provided between an internal pipe and an external pipe along the center line of a double pipe. In the cross section of a bent portion as viewed in a direction along the center line of the double pipe, the first spacer is located inwardly relative to the center of the double pipe with reference to the radial direction of the bent portion. The second spacer is located outwardly relative to the center of the double pipe. When a straight line that passes through the center of the radius of the bent portion and through the center of the double pipe is taken as a reference line at least either one of the first spacer or the second spacer overlaps the reference line.

A fluid conduit has a longitudinal flow passage which includes a transverse cross section that is configured as a polygon, such as a convex or a concave polygon.

One aspect of the invention provides a composite refrigeration line set including: a suction line and a return line. One or more of the suction line and the return line are a composite refrigeration line set tube including: an inner plastic tube; a first adhesive layer circumferentially surrounding the inner plastic tube; an aluminum layer circumferentially surrounding the first adhesive layer and coupled to the inner plastic tube via the first adhesive layer; a second adhesive layer circumferentially surrounding the aluminum layer; and an outer plastic layer circumferentially surrounding the aluminum layer coupled to the aluminum layer via the second adhesive layer. The inner plastic tube is polyethylene of raised temperature. The outer plastic tube is polyethylene of raised temperature. The aluminum layer includes an alloy selected from the group consisting of: AL 3004-O, AL 3005-O, and AL 3555-O. The aluminum layer is butt-welded to itself.

One aspect of the invention provides a composite refrigeration line set including: a suction line and a return line. One or more of the suction line and the return line are a composite refrigeration line set tube including: an inner plastic tube; a first adhesive layer circumferentially surrounding the inner plastic tube; an aluminum layer circumferentially surrounding the first adhesive layer and coupled to the inner plastic tube via the first adhesive layer; a second adhesive layer circumferentially surrounding the aluminum layer; and an outer plastic layer circumferentially surrounding the aluminum layer coupled to the aluminum layer via the second adhesive layer. The inner plastic tube is polyethylene of raised temperature. The outer plastic tube is polyethylene of raised temperature. The aluminum layer includes an alloy selected from the group consisting of: AL 3004-O, AL 3005-O, and AL 3555-O. The aluminum layer is butt-welded to itself

A duct bank assembly may include an elongate extending conduit with a length for receiving and passing through a cable or wire and an encasing body encasing the conduit along its longitudinal extent between a first mating end and an opposed second mating end of the body. Each mating end of the at least one elongate conduit has a male or female mating end for joining with a corresponding male or female mating end of an abutting duct bank assembly in a self-locking, self-sealing joint.