RU62198U1 - COMBINED PIPE WITH BALLAST COATING IN THE SHELL - Google Patents

Abstract

The invention relates to pipeline technology, namely to pipes with a ballast coating, used when laying pipelines along the bottom of reservoirs and in wetlands. The pipe combined with heat insulating and ballast coatings consists of a central pipe that conducts the substance in a liquid state; a first sheath pipe with an inner diameter greater than the outer diameter of the central pipe mounted coaxially with the central pipe to form a first annular space; the first supporting-guide device located in the first annular space, consisting of centralizers with supports; thermal insulation material filling the first annular space; a second shell pipe mounted to form a second annular space; a second supporting-guide device located in the second annular space; ballast material filling the second annular space, while the second shell pipe is spiral-wound from galvanized steel tape and has a protective coating on the outer surface, which can be either single-layer, for example, polyethylene, or multilayer (two- or three-layer), which last layer is made of polyethylene. The central pipe can be either steel or polyethylene. 7 pf, 3 fig.

Description

The invention relates to pipeline technology, namely, ballast-coated pipes used in laying pipelines along the bottom of water bodies.

A known construction of a pipe for an underwater oil pipeline [1, Fig. 1.6c, p.12], consisting of a central steel pipe, a heat-insulating layer of polyurethane foam, a steel casing protecting the heat-insulating layer, a protective coating of the steel casing and a weight coating.

A disadvantage of the known pipe is that there is no casing protecting the weighting coating from destruction in the aquatic environment.

A known pipe with thermal insulation in a waterproof sheath [2, 3], having a Central steel pipe and a spiral sheath made of galvanized steel sheet, centering rings installed between the Central steel pipe and a spiral sheath, forming an annular gap filled with rigid polyurethane foam. The disadvantage of this pipe is that it is not suitable for laying on the bottom of reservoirs or in wetlands, therefore, it does not have protective insulation on a spiral-sheath, and in the case of protective insulation, the application of ballast devices is required that do not always prevent the pipe from floating if it emptying.

Known combined pipe [4, p.f. 6, 8, p.13, FIGS. 1-5], designed to transport water, gas, oil, etc., having a central metal pipe, a layer of protective anticorrosive coating on it, a layer of thermal insulation material, a layer of material that protects thermal insulation from mechanical impacts and the last layer of ballast material. The disadvantage of the pipe is that the outer surface of the ballast

material (mainly concrete) is not protected from the constant destructive effects of the external aquatic environment.

Known combined heat-insulated pipe with a coating of concrete as a weighting and waterproofing material, in which the heat-insulating layer is separated from the concrete layer by a polyethylene pipe, and the concrete is placed in the outer polyethylene sheath [5, p. 3, p. 22, Fig. 5, 6 ].

A disadvantage of the known combined pipe is that the polyethylene pipe separating the heat-insulating layer from the concrete and the polyethylene sheath covering the concrete layer have smooth surfaces, so when lowering into water or an aqueous medium using a tensioner, it is possible to displace the central pipe with a layer of thermal insulation relative to the inner surface of the concrete layer, and the Central pipe with heat-insulating and concrete layer relative to the shell, clamped in a tension device.

The technical task is to create a combined pipe, in which the displacement of the central pipe with a heat-insulating layer in the polyethylene pipe relative to the inner surface of the concrete layer and the outer polyethylene sheath, clamped in the tension device relative to the concrete layer during laying on the bottom of the reservoir, is eliminated.

The problem is solved in the construction of a pipe combined with heat-insulating and ballast coatings, consisting of a central pipe that conducts the substance in a liquid state; a first sheath pipe with an inner diameter greater than the outer diameter of the central pipe and a length shorter than the length of the central pipe installed coaxially with the central pipe to form a first annular space; the first supporting-guide device located in the first annular space, consisting of centralizers with supports distributed and fixed on the surface of the central pipe; thermal insulation material filling the first annular space; second shell pipe with inner

a diameter larger than the outer diameter of the first shell, and a length less than or equal to the length of the first shell established to form a second annular space; a second support-guide device located in the second annular space, consisting of centralizers with supports distributed and fixed on the surface of the first shell; ballast material filling the second annular space, while the second shell pipe is spiral-wound from galvanized steel tape and has a protective coating on the outer surface, which can be either single-layer, for example, polyethylene, or multilayer (two- or three-layer), which last layer is made of polyethylene.

The first sheath pipe is made of a polymer or composite material, but preferably spiral-wound galvanized steel tape.

If the first pipe-shell is polyethylene, then it has on the outer surface annular protrusions of preferably rectangular shape made of polymer tape, providing better adhesion to the ballast material. Ballast material reinforced with steel reinforcement mounted on centralizers is preferred.

The central pipe may be steel with a protective anti-corrosion coating or of polyethylene or other polymeric or composite material.

A new feature of the combined pipe: the second sheath pipe is a spiral-wound galvanized steel strip and has a protective coating on the outer surface. This feature provides a technical effect: an increase in the adhesion force between the outer shell, by which the pipe is gripped and held during installation, and the outer surface of the ballast material. The increased adhesive force eliminates the shear of the sheath pipe relative to the outer surface of the ballast material.

If the first sheath pipe is a spiral-wound galvanized steel strip, then it provides better adhesion to the inner surface of the ballast material than a polyethylene pipe.

The annular protrusions on the outer surface of the first pipe-shell made of polyethylene also provide its better adhesion to the inner surface of the ballast material. If the annular protrusions are rectangular, then the adhesion to the inner surface of the ballast material is further increased.

Both the first distinguishing feature of a combined pipe, and the combination of features are new, since they were not found in the analysis of the prior art.

Figures 1 and 2 show a longitudinal section of a pipe combined with heat-insulating and ballast coatings.

In Fig.3 is a transverse section of the combined pipe shown in Fig.1.

The pipe combined with a ballast coating in the shell (Fig.1-3) consists of a Central pipe 1,

the first shell pipe 2 with an inner diameter greater than the outer diameter of the central pipe 1, and a length shorter than the length of the central pipe 1, mounted coaxially with the central pipe to form the first annular space 3,

the first supporting-guide device located in the first annular space 3, consisting of centralizers 4, distributed and fixed on the surface of the Central pipe 1; heat-insulating material 5 filling the first annular space,

a second sheath pipe 6 with an inner diameter greater than the outer diameter of the first sheath pipe 2 installed coaxially with the first sheath pipe to form a second annular space 7 having a ballast filler 8;

the second supporting-guide device, located in the second annular space, consisting of centralizers 9, distributed and fixed on the surface of the first shell pipe 2.

The second pipe-shell 6 has on the outer surface a protective coating 10, single-layer or multi-layer. A single layer protective coating 10 is made of polyethylene. The outer layer of the multilayer protective coating is preferably polyethylene.

If the first pipe-shell 2 is polyethylene, then to increase adhesion to the ballast material 8, rectangular rings 11 of a polymer tape are wound on its outer surface (Fig. 1). If the first pipe-shell 2 is spiral-wound (FIG. 2), then its adhesion to the ballast material increases due to its waviness.

In the proposed combination pipe, the central pipe may be made of polyethylene (figure 2).

To increase the bending strength of the pipe, the ballast filler is reinforced with steel reinforcement 12, mounted on tapes or wire 13 of the centralizers 9 (figure 2).

When assembling the combined pipe (Figs. 3, 6), the central pipe 1 with centralizers 4 and the first sheath pipe 2 is first assembled and the annular space 3 is filled with heat-insulating material 5, then centralizers 8 are installed on the first shell and, if necessary, they are installed and fixed the reinforcement 12 on the tapes 13, collect the insulated pipe with the second sheath 6, install plugs (not shown) at the ends of the second sheath 6 and fill the second annular space with cement-containing ballast material 9, withstand until solid evaniya ballast material 9 and remove the stub.

When laying on the bottom of the reservoir, the pipeline is held in a tension device covering the second sheath pipe 6, which is pressed by the clamps of the tension device to the ballast material, eliminating shear

ballast material 8 with heat-insulating material 5 and the Central pipe 1 relative to the shell 6.

The pipe combined with a ballast coating has negative buoyancy and is held in a trench at the bottom of a reservoir without weights due to its own gravity even in the absence of a transported liquid medium. The shell provides reliable protection of the ballast material from destruction by the flow of water and from other destructive effects.

Information sources:

1. Borodavkin P.P. and other underwater pipelines. M., Nedra, 1979, 415 p.

2. PM RU No. 49167 dated 04/20/2005.

3. PM RU No. 49166 dated 04/20/2005.

4. Patent WO No. 03/095887 A1 of March 30, 2003.

5. Patent RU No. 2246658 C1 of March 19, 2004.

Claims (7)

1. Combined pipe, consisting of a central pipe conducting a substance in a liquid state; a first sheath pipe with an inner diameter greater than the outer diameter of the central pipe and a length shorter than the length of the central pipe installed coaxially with the central pipe to form a first annular space; the first supporting-guide device located in the first annular space, consisting of centralizers with supports distributed and fixed on the surface of the central pipe; thermal insulation material filling the first annular space; a second shell pipe with an inner diameter greater than the outer diameter of the first shell and a length less than or equal to the length of the first shell established to form a second annular space; a second support-guide device located in the second annular space, consisting of centralizers with supports distributed and fixed on the surface of the first shell; ballast material filling the second annular space, characterized in that the second sheath pipe is a spiral-wound galvanized steel strip and has a protective coating on the outer surface. 2. The combined pipe according to claim 1, characterized in that the protective coating of the second shell pipe is multilayer, the last layer being made of polyethylene. 3. The combined pipe according to claim 1, characterized in that the first sheath pipe is a spiral-wound galvanized steel strip. 4. The combined pipe according to claim 1, characterized in that the first sheath pipe is polyethylene and has annular protrusions on the outer surface. 5. The combined pipe according to claim 4, characterized in that the annular protrusions are made of polymer tape and have a rectangular shape. 6. The combined pipe according to claim 1, characterized in that the central pipe is made of polyethylene. 7. The combined pipe according to claim 1, characterized in that the ballast material has steel reinforcement mounted on centralizers.