A method of fabricating a conduit comprises steps of attaching a first tubular-outboard-ply end of a tubular outboard ply to a first inner collar portion of a first collar with a third weld and attaching a second tubular-outboard-ply end to a second inner collar portion of a second collar with a fifth weld. The method additionally comprises steps of interconnecting the first inner collar portion and a first outer collar portion of the first collar with a first weld and interconnecting the second inner collar portion and a second outer collar portion of the second collar with a sixth weld. The method also comprises attaching a trimmed first corrugated-inboard-ply end to the first outer collar portion with a second weld, attaching a trimmed second corrugated-inboard-ply end to the second outer collar portion with a fourth weld, and communicatively coupling a first sensor with an interstitial space.

A method of fabricating a conduit comprises steps of attaching a first tubular-outboard-ply end of a tubular outboard ply to a first inner collar portion of a first collar with a third weld and attaching a second tubular-outboard-ply end to a second inner collar portion of a second collar with a fifth weld. The method additionally comprises steps of interconnecting the first inner collar portion and a first outer collar portion of the first collar with a first weld and interconnecting the second inner collar portion and a second outer collar portion of the second collar with a sixth weld. The method also comprises attaching a trimmed first corrugated-inboard-ply end to the first outer collar portion with a second weld, attaching a trimmed second corrugated-inboard-ply end to the second outer collar portion with a fourth weld, and communicatively coupling a first sensor with an interstitial space.

A double-wall spiral welded pipe includes a first steel belt layer and a second steel belt layer which have equal widths, are arranged in parallel and align with each other; at least two supporting steel bars perpendicular to the first steel belt layer and the second steel belt layer are arranged between the first steel belt layer and the second steel belt layer; the supporting steel bars are arranged on end parts of two sides of the first steel belt layer and the second steel belt layer and extend together with the first steel belt layer and the second steel belt layer; and the first steel belt layer, the second steel belt layer and the supporting steel bars on the end parts of the two sides are mutually welded to form a double-layer composite steel belt with a rectangular section in an extending direction.

A double-wall spiral welded pipe includes a first steel belt layer and a second steel belt layer which have equal widths, are arranged in parallel and align with each other; at least two supporting steel bars perpendicular to the first steel belt layer and the second steel belt layer are arranged between the first steel belt layer and the second steel belt layer; the supporting steel bars are arranged on end parts of two sides of the first steel belt layer and the second steel belt layer and extend together with the first steel belt layer and the second steel belt layer; and the first steel belt layer, the second steel belt layer and the supporting steel bars on the end parts of the two sides are mutually welded to form a double-layer composite steel belt with a rectangular section in an extending direction.

A double pipe includes an inner pipe through an interior of which low pressure gaseous cooling medium flows and an outer pipe having the inner pipe in its interior, the outer pipe being configured such that high-pressure liquid cooling medium flows between the inner pipe and the outer pipe, wherein the inner pipe has a plate member that extending in the longitudinal direction so as to partition the interior of the inner pipe into a plurality of chambers. The plate member has a helical shape along the longitudinal direction.

A double pipe includes an inner pipe through an interior of which low pressure gaseous cooling medium flows and an outer pipe having the inner pipe in its interior, the outer pipe being configured such that high-pressure liquid cooling medium flows between the inner pipe and the outer pipe, wherein the inner pipe has a plate member that extending in the longitudinal direction so as to partition the interior of the inner pipe into a plurality of chambers. The plate member has a helical shape along the longitudinal direction.

Provided is a clad welded pipe or tube that has improved pipe or tube mechanical properties by reducing the width of a weld without its function as a clad pipe or tube being impaired. A clad welded pipe or tube comprises: a first layer made of base metal; and a second layer placed on one surface of the first layer, and made of first cladding metal that is a material different from the base metal, wherein a pipe or tube circumferential length L1 of weld metal at a pipe or tube inner surface and a pipe or tube circumferential length L2 of the weld metal at a pipe or tube outer surface in a weld are each 0.0010 mm or more and 1.0 mm or less, and the base metal is not exposed at a first cladding metal-side surface of the clad welded pipe or tube in the weld.

Provided is a clad welded pipe or tube that has improved pipe or tube mechanical properties by reducing the width of a weld without its function as a clad pipe or tube being impaired. A clad welded pipe or tube comprises: a first layer made of base metal; and a second layer placed on one surface of the first layer, and made of first cladding metal that is a material different from the base metal, wherein a pipe or tube circumferential length L1 of weld metal at a pipe or tube inner surface and a pipe or tube circumferential length L2 of the weld metal at a pipe or tube outer surface in a weld are each 0.0010 mm or more and 1.0 mm or less, and the base metal is not exposed at a first cladding metal-side surface of the clad welded pipe or tube in the weld.

Provided is a thermal-insulated multi-walled pipe for superconducting power transmission that highly prevents intrusion of external heat due to radiation and has excellent thermal insulation property without using a superinsulation. A thermal-insulated multi-walled pipe for superconducting power transmission comprises: a superconducting cable; and a multi-walled pipe that houses the superconducting cable, wherein the multi-walled pipe is composed of a plurality of straight pipes, and at least one of the plurality of straight pipes has, at a surface thereof, a zinc or zinc alloy-plated layer having an average spangle size of 2.0 mm or less.

A pipe fitting for conveying a medium, including an inlet at which the medium enters in a first direction perpendicular to an inlet cross section, and an outlet at which the medium leaves in a second direction perpendicular to an outlet cross section, wherein the two directions enclose an angle. The pipe fitting has three parts, wherein in each case two parts bearing against one another at a contact point, wherein in each case two parts at their contact point being rotatable relative to one another about the axis of the flow direction at the contact point in order to change the angle, and wherein the two contact points being spaced apart from one another in the flow direction.