An expiratory limb for a breathing circuit includes an enclosing wall defining a flexible singular expiratory flow passage between an inlet and an outlet and bounding the flexible singular expiratory flow passage and ambient air. The expiratory limb includes one or more regions of the enclosing wall that made from a material that allows passage of water vapor without allowing passage of liquid water, thereby forming a water vapor flow path from the flexible singular expiratory flow passage to the ambient air through the material. The expiratory limb is configured to allow diffusion of water vapor along the flexible singular expiratory flow passage and dry the flow of expiratory gases between the inlet and the outlet.

To produce a flexible pipe body, a length of tensile armour element (300) of pre-preg composite material is fed towards a fluid-retaining layer (602). The tensile armour element (300) passes through a guide (604) an a pre-heater (606). The tensile armour element (300) is then applied to the fluid-retaining layer (602), being wrapped around the fluid-etaining layer (602) by virtue of the rotation of the layer (602), the linear translation of the layer (602), and the fixed position of the tensile armour element feed (601). The element (300) is fed to the fluid-retaining layer under a constant, predetermined controlled tension. Positioning head (608) helps to position the element (300) on the fluid-retaining layer (602). As tensile armour element is wound onto the pipe body, the pipe body continues to move in a, linear direction and the pipe body moves through an oven (610).

To produce a flexible pipe body, a length of tensile armour element (300) of pre-preg composite material is fed towards a fluid-retaining layer (602). The tensile armour element (300) passes through a guide (604) an a pre-heater (606). The tensile armour element (300) is then applied to the fluid-retaining layer (602), being wrapped around the fluid-etaining layer (602) by virtue of the rotation of the layer (602), the linear translation of the layer (602), and the fixed position of the tensile armour element feed (601). The element (300) is fed to the fluid-retaining layer under a constant, predetermined controlled tension. Positioning head (608) helps to position the element (300) on the fluid-retaining layer (602). As tensile armour element is wound onto the pipe body, the pipe body continues to move in a, linear direction and the pipe body moves through an oven (610).

A breathing circuit component includes an inlet, an outlet and an enclosing wall. The enclosing wall defines a gases passageway between the inlet and the outlet. At least a region of the enclosing wall is formed from a breathable material that allows the passage of water vapor without allowing the passage of liquid water or respiratory gases. The breathing circuit component may be the expiratory limb of a breathing circuit.

A breathing circuit component includes an inlet, an outlet and an enclosing wall. The enclosing wall defines a gases passageway between the inlet and the outlet. At least a region of the enclosing wall is formed from a breathable material that allows the passage of water vapor without allowing the passage of liquid water or respiratory gases. The breathing circuit component is the expiratory limb of a breathing circuit.

In a filament winding method, while a rotating tank relatively reciprocates in a tank axial direction to a helical winding head, fibers are fed from yarn-feeding sections to the tank. After the tank turns back in the tank axial direction, a large number of fibers are wound around one domed portion and a trunk portion of the tank, and trailing ends of the large number of fibers are located at one end portion of the trunk portion. Then a piece or a small number of fibers are fed from a rotating hoop winding head to the trunk portion, and hoop winding is performed on helical winding layers formed around the trunk portion. Then, at the one end portion of the trunk portion, the large number of fibers pulled from the yarn-feeding sections of the helical winding head are cut off.