A system and method for forming a strut. A strut comprises a laminated composite tube having a substantially hollow interior and a pair of longitudinal stiffeners attached to opposite sides of the laminated composite tube.

An elongate tubular shaft body having a stack of wrapped layers of fibrous reinforcement in a resin matrix, a portion of the stack of wrapped layers circumferentially surrounding a first surface part of a fibrous layer has a non-constant width which varies non-linearly with a change in radius of an inner elongate circumferential surface in the portion, and wherein the fibrous reinforcement has fibres that are, along the length of the elongate tubular body, constantly oriented with respect to a cylindrical coordinate system about the longitudinal axis of the elongate tubular body, the fibre orientation in any said portion being independent of the geometry of the inner and outer elongate circumferential surfaces of that portion.

A pipe includes an elongate strip wound into a tubular pipe form with the upper surface and the ribs at an exterior of the tubular pipe form, and with a first portion of a first side overlapping a first portion of a second side along a helical joint. A plastic seam weld is applied between the overlapping first portions for bonding the overlapping first portions together. A plastic overweld extends over the overlapping first portions and over both a second portion of the first side and a second portion of the second side. The second portion of the first side is adjacent to the first portion of the first side and does not overlap with any part of the second side, and the second portion of the second side is adjacent to the first portion of the second side and does not overlap any part of the first side.

There is provided a flexible, helically wound conduit for a breathing circuit comprising an inlet 1, an outlet 3, and an enclosing wall 2 defining a flow passage between said inlet and said outlet, wherein at least a region of said enclosing wall is permeable to water vapor and one or more of O.sub.2 and CO.sub.2, and wherein the axial tensile strength of the enclosing wall is greater than 40N. Further provided are limbs comprising the conduit, a method of manufacturing the conduit and the use of the conduit to remove water vapor and/or CO.sub.2 from gas exhaled by a patient.

A flexible hose assembly includes a length of tubular hose formed from a spiral-wrapped layer of polymer material. A helical stiffener is disposed on an outer surface of the tubular hose. The helical stiffener comprises an elastomer material that is configured to bond or adhere to the polymer material of the tubular hose.

Tubular structures, systems, and methods are generally directed to support structures having structural properties similar to thick-walled structures while being formed using materials having thickness amendable to rolling and welding and, thus, useful for rapid and cost-effective fabrication.

A flexible hose assembly includes a length of tubular hose formed from a spiral-wrapped layer of polymer material. A helical stiffener is disposed on an outer surface of the tubular hose. The helical stiffener comprises an elastomer material that is configured to bond or adhere to the polymer material of the tubular hose.

An pneumatic plug for sealing a pipeline. The pneumatic plug includes a tubular member that extends in an axial direction from a first end to a second end. The tubular member includes a rubber layer and a fiber layer. The rubber layer extends from the first end to the second end of the tubular member. The fiber layer is disposed on a top surface of the rubber layer. The fiber layer includes a plurality of fibers that extend from the first end to the second end of the tubular member. Each of the plurality of fibers extend at an angle that is offset from the axial direction.

An pneumatic plug for sealing a pipeline. The pneumatic plug includes a tubular member that extends in an axial direction from a first end to a second end. The tubular member includes a rubber layer and an elastomeric band. The rubber layer extends from the first end to the second end of the tubular member. The elastomeric band is disposed on a top of the rubber layer. The elastomeric band is positioned between the first end and the second end of the tubular member.

A composite structure having at least one radially extending part is provided. The composite structure is formed with ply layers. At least one of the ply layers used to form the radially extending part has fibers oriented at an angle offset from an edge of the at least one ply layer.