GB2280009A - Floating pipe - Google Patents

Abstract

A floating pipe for the transport of fluids, particularly hydrocarbons, comprises an internal sealing sheath (1), a woven textile stiffener (2) adhered to the sealing sheath (1) around the exterior thereof and an external sheath (4) extruded onto the exterior of the stiffener and encompassing two flotation sheaths (3) which are diametrically opposed being disposed longitudinally of the pipe and adjacent the exterior of the stiffener. <IMAGE>

Description

FLOATING PIPE The invention concerns the field of pipes, used for the transport of fluid having a specific gravity close to or less than that of water, and in particular for the transport of hydrocarbons. It also concerns pipes equipped with means which allow them to float when they are extended over an expanse of sea.

In a general manner, these pipes comprise an internal sealing sheath made of a material resistant to the transported fluid, a reinforcement stiffener, and at least one external protective sheath.

The means enabling them to float are incorporated between the internal and external sheaths, and are constituted either by a cellular material having a low specific gravity, as described in FR-A 2.203.957 and FR-A 2.418.404, or by a space adapted to contain air, as in FR-A 2.082.031, or by tubular sections embedded in a similar material, as described in FR-A 2.294.379, or, finally, by flotation sheaths having closed ends and disposed helicoidally about a reinforcing support, as in GB-A 1.361.215.

Because of their structure, presently available floating pipes are costly to make and are of economic interest only for applications which necessitate continuous usage. Moreover, their bulky structure makes it difficult to coil them up.

The aim of the present invention is to provide a low cost floating pipe, which can be used for the transport of various fluids, and in particular hydrocarbons, for permanent applications as well as for temporary ones, and for example, for the recovery of hydrocarbons polluting the surface of an expanse of sea.

To this end, in the pipe of the invention, the flotation sheaths, of which there are two, are diametrically opposed and disposed longitudinally and are held by the external sheath which is directly extruded onto them and onto the stiffener.

In a preferred embodiment, the flotation sheaths are two in number and are diametrically opposed along the main pipe.

With this arrangement, the pipe is flattened preferentially between the flotation sheaths, producing a thickness at least equal to the diameter of these sheaths. The floating pipe, thus flattened, may very easily be stored in the form of a ring or on a drum, which reduces its bulk and guarantees its preservation.

Other characteristics and advantages will become clear from the following description, by way of example, with reference to the accompanying schematic drawing of which the single figure shows one embodiment of this pipe in transverse cross-section.

In the drawing, the reference 1 designates an internal sealing sheath, of material resistant to hydrocarbons and, for example, of rubber or synthetic material. The reference 2 designates a woven textile stiffener providing the mechanical reinforcement of the pipe and its resistance to pressure. This stiffener adheres to the internal sealing sheath.

The reference 3 designates the two flotation sheaths made by extrusion of a synthetic material, such as polyethylene, or in natural or synthetic rubber. The flotation sheaths 3 have a diametric measurement less than that of the actual pipe. Their internal diameter is defined such that the cylindrical chambers which they form are sufficient to give the empty pipe assembly a specific gravity lower than that of water. In fact, since the fluid transported by the pipe has a density at least equal to 1, it is necessary only that the flotation sheaths counterbalance the weight of the pipe assembly thus produced, in order to ensure the ability of the pipe to float.

The two flotation sheaths are disposed longitudinally of the pipe and are diametrically opposed.

The reference 4 designates the external sheath enveloping the textile stiffener 2 and the flotation sheaths 3, ensuring the cohesion of the assembly and its mechanical protection.

This external sheath is made of a material very resistant to tearing and abrasion, for example of a polyurethane elastomer. It is extruded directly onto the textile stiffener and the flotation sheaths and connects them together.

When a section of any length is cut, its ability to float is ensured by closing each of the ends of the sheaths 3, either by plugs, or by welding.

In known manner, the sealed length thus obtained may, before final closure of its last end, be inflated with air under pressure.

Such a floating pipe may be used for any transport or delivery of liquid passing across the surface of an expanse of water, such as lake, river or sea. It may also be used in a procedure to depollute the surface of an expanse of water, for example, by connection to the outlet of a pump aspirating a pollutant layer floating on this expanse. In these conditions, the floating pipe permits the evacuation of pollutant fluid towards the bank, whilst itself remaining visible on the surface of the water.

Claims (2)

1. A floating pipe of the type comprising a sealed internal sheath made of a material resistant to the transported fluid, a reinforcement stiffener, flotation sheaths of smaller transverse dimension than that of the internal sheath disposed adjacent the reinforcement stiffener and of which the ends are closed, and an external sheath enveloping the assembly, the flotation sheaths being two in number, diametrically opposed, extending longitudinally of the pipe, and being held by the external sheath which is directly extruded onto them and onto the stiffener.

2. A floating pipe substantially as hereinbefore described, with reference to the accompanying drawings.