RU88767U1 - ROCK SHEET - Google Patents

Abstract

1. Rock sheet containing a hollow open cylinder formed by a flexible cloth, characterized in that the flexible cloth is made of at least one layer of multiaxial fabric based on fiberglass with a total thickness of not more than 5.5 mm and a surface density of not more than 4, 5 kg / m2, while the flexible panel is impregnated to the full thickness with a polymer composition based on PVC, acrylic or urea-formaldehyde resin, with a total polymer composition consumption of not more than 3.5 kg / m2. ! 2. The rock sheet according to claim 1, characterized in that the flexible sheet is made of three layers of multiaxial fabric, while the two outer layers are made of fiberglass-based fabric, and the middle layer is of a nonwoven needle-punched synthetic fabric.

Description

The inventive rock sheet belongs to the field of construction and can be used to protect against damage by sharp edges of permafrost and rocky ground insulation coating of pipelines during their underground laying.

Known protective device containing a hollow open cylinder with an external solid after special surface treatment. The hollow cylinder is made of a flexible cloth based on synthetic material (see US 4413656 A, 1982, F16L 57/00).

A disadvantage of the known solution is the difficulty in manufacturing the panel from the polymer composition, as well as the need for heat treatment to obtain a device with the necessary hardness of the outer surface.

It is also known shockproof protective device of various surfaces, mainly the pipeline, which is placed on the pipeline, crimped along its perimeter and secured, for example, with ties. The device comprises a hollow open cylinder with an external solid surface after special processing, formed by a flexible cloth made of synthetic material. The blade is made of fibrous sheet nonwoven material based mainly on fibers of the group of polyesters, polyamides or polyolefins. The plate has a thickness of mainly 9 ^± 3 mm. The outer area of the panel is filled with a self-hardening composition based on carbomido (melamine) formaldehyde resin, hardener and plasticizer with a total flow rate of mainly 5 ^± 1.5 kg / m ² . (see RU 2162187 C1, 01.20.2001).

A disadvantage of the known device is a rather complicated manufacturing technology and high consumption of materials.

The closest in technical essence and the achieved result to the claimed is a rock sheet for the protection of pipelines. It contains a hollow open cylinder formed by a flexible panel of synthetic material. A flexible panel with a total thickness of not more than 7 ± 0.5 mm is made single or double layer of sheet fibrous nonwoven material based on fibers of the polypropylene or polyester group. The thickness of the fibrous nonwoven material is 3.5 ÷ 7.0 ± 0.5 mm. The fibrous nonwoven material is impregnated to the entire thickness with a self-curing composition based on urea-formaldehyde resin. The total consumption of the composition is not more than 7.0 ± 0.5 kg / m ² . (see RU2214553 C1, IPC 7 F16L 57/00, 2003.10.20).

The disadvantage of this invention is the insufficiently high physical and mechanical properties of the rock sheet. This is due to the properties of the fibers of the polypropylene group or polyesters, which absorb moisture from the soil. As a result, formaldehyde resin swells and destroys the rock sheet. In addition, the disadvantage is the complexity of the technological process of production of rock sheet.

The technical result that is achieved in the claimed utility model is to increase the physical and mechanical properties of the rock sheet, thereby increasing the reliability of the device while maintaining the flexibility of the rock sheet during transportation and installation on the pipeline in the field.

The technical result is achieved in a rock sheet containing a hollow open cylinder formed by a flexible plate. The flexible panel is made of at least one layer of multiaxial fabric based on fiberglass with a total thickness of not more than 5.5 mm and a surface density of not more than 4.5 kg / m ² . At the same time, the flexible panel is impregnated to the full thickness with a polymer composition based on PVC, acrylic or urea-formaldehyde resin. The total consumption of the polymer composition is not more than 3.5 kg / m ² .

In addition, the flexible panel can be made of three layers of multiaxial fabric. In this case, the two outer layers are made of fiberglass-based fabric, and the middle layer is of a nonwoven needle-punched synthetic fabric.

The inventive rock sheet is illustrated by drawings, where:

Figure 1 - three-layer flexible panel in cross section;

Figure 2 - diagram of the use of rock sheet on the pipeline.

As shown in FIGS. 1 and 2, the rock sheet is a hollow open cylinder (not indicated in the drawing) made of flexible web 1. Flexible web 1 can contain one or more layers of multi-axial fabric. Consider the example when the flexible web 1 consists of three layers. Figure 1 shows a three-layer flexible cloth 1. It consists of two outer layers 2 of a multiaxial fabric based on fiberglass, and an inner layer 3 of a polymer non-woven cloth located between the outer layers 2. Such a flexible cloth is stitched on both sides and impregnated with a polymer composition on based on PVC, acrylic or urea-formaldehyde resin. If the flexible web consists of one layer 2 of multiaxial fabric, then it is simply impregnated with a polymer composition over the entire thickness of layer 2. The impregnation for a three-layer flexible web 1 is carried out on both sides, that is, on the side of layer 2 of multiaxial fabric. The total consumption of the polymer composition should not exceed 3.5 kg / m ² .

The optimum layer thickness is 3 ± 1 mm. With a thickness of less than 3 mm, the impact load that it can withstand is reduced. With greater thickness, its cost increases.

Layer 2 of multiaxial fabric provides strength and stiffness of the flexible web 1 for tensile, tearing, bending, puncture. If three layers are used in the rock sheet, then the polymer non-woven fabric 3 provides damping of shock loads that occur when backfilling with large fractions of frozen or rocky soil and when laying the pipeline in permafrost areas.

Flexible web 1 is made up to 5 ± 0.5 mm thick, up to 126 ± 1 cm wide and with a surface density of not more than 4.0 + 0.5 kg / m ² .

The length of the rock sheet is selected depending on the diameter of the pipeline.

Claimed rock sheet is stable in environments with pH from 3 to 10 inclusive. In this case, the residual breaking load is at least 90%. It is resistant to mold. The inventive rock sheet withstands bending of 180 ° without visually observed destruction of the fibers with a bending radius of 300 mm at a temperature of minus 20 ° C. Impact resistance of at least 24 J according to GOST 4765, according to the R-381-80 method, at least 60 J.

The claimed rock sheet is frost-resistant and can withstand 50 cycles of freezing - thawing in distilled water (from minus 15 ° C to plus 18 ° C), while the reduction in breaking load does not exceed 10% of the original. The loss of strength in an acidic and alkaline environment is not more than 45% after exposure for 24 hours at a temperature of 20-25 ° C. Moisture absorption - not more than 5% when aged in water for 24 hours at 20 ° C.

The service life of the declared rock sheet is 30 years, subject to the performance requirements.

Claimed rock sheet applies:

- To protect the insulated surface of pipes or pipe sections for the period of transportation and installation work.

- To protect the insulated surface of the pipeline when it is backfilled with rocky or frozen soil.

- To protect during operation from the action of sharp edges of rocky soil when moving the pipeline in the ground.

- For lining the working lashes of pipelines at crossings through roads, air passages through ravines, rivers, etc., at underwater crossings, including at sites ballasted by ring weighting agents.

Figure 2 shows an example of the use of the claimed rock sheet 4 on the pipeline 5. The rock sheet 4 is fixed on the insulated surface of the pipeline 5 after unloading from transport or directly when laying the pipeline in a trench. The rock sheet 4 is wrapped across the pipeline 5 and secured with bandage ties 6 from a polymer packaging tape. Bandage ties 6, in the amount of 2 pieces per rock sheet, are placed at a distance of 100-150 mm from the edges. They are pulled together with a clamping device and fastened with metal buckles 7. The tightening force should exclude the possibility of displacement of the rock sheet 4 along the surface of the pipeline 5. The longitudinal joint of the rock sheet is located in the lower part of the pipeline and is overlapped. The double layer of rock sheet 4 thus formed provides additional protection for the lower part of the pipeline in the zone of action of maximum indentation forces when lowering it into the trench. The overlap is 60 ° along the cross section of the pipeline. Cross docking of rock sheets 4 is also carried out with an overlap of 80-100 mm.

The pipeline laid in the trench is covered (with a single-bucket excavator from a low height) with rocky or frozen soil with fraction sizes not exceeding 70 mm to a level 300 mm higher than its upper generatrix. Further backfilling of the trench is done with a bulldozer. When laying in a trench formed by explosive methods, at the bottom of the trench, they add gravel, sand with a layer thickness of at least 100 mm to prevent direct contact of the lined pipeline with sharp edges of rocks. If it is necessary to use rocky soil with a size of fractions up to 100 mm for primary filling of pipelines, the surface of the pipeline laid in the trench is additionally covered with a second layer of rock sheet 4, laying it along the axis of the pipeline and securing it with bandages 6 every 2 m.

The length and weight of the rock sheet used, depending on the outer diameter of the pipeline, are given in table 1.

Table 1. Nominal outside diameter of the pipeline, mm (GOST R 52079) Rock sheet length, mm (± 5 mm), not less The mass of the rock sheet with a thickness of 4 mm, kg 114 420 1.8 ± 0.1 121 445 1.9 ± 0.1 133 490 2.1 ± 0.1 140 515 2.2 ± 0.1 159 585 2.5 ± 0.1 168 620 2.7 ± 0.1 219 805 3.4 ± 0.1 245 900 3.9 ± 0.2 273 1000 4.3 ± 0.2 325 1195 5.1 ± 0.2 377 1385 5.9 ± 0.2 426 1565 6.7 ± 0.2 530 1945 8.3 ± 0.3 630 2310 9.9 ± 0.3 720 2640 11.3 ± 0.3 820 3005 12.9 ± 0.4 1020 3740 16.0 ± 0.5 1220 4470 19.1 ± 0.6 1420 5200 22.3 ± 0.7

Physico-mechanical characteristics of the claimed rock sheet are shown in table 2.

Table 2. Material Width, cm 126 ± 1 Material Thickness, mm 3.0-4.0 Surface density, g / m ² 3000-4200 Chemical resistance in acidic and alkaline environments - loss of strength after exposure for 24 hours at 20-25 ° C,%, not more than 45 Impact resistance, J, according to the R-381-80 method, not less 60 Expandability under the static action of a vertical load with a specific pressure of 1.25 kgf / cm ² without destruction Breaking load in the longitudinal direction at + 23 ° С, (strips 50 × 220 mm) kgf, not less 450 Breaking load in the longitudinal direction at -30 ° С, (strips 50 × 220 mm) kgf, not less 400 Breaking load in the transverse direction at + 23 ° С, (strips 50 × 220 mm) kgf, not less 410 Breaking load in the transverse direction at -30 ° С, (strips 50 × 220 mm) kgf, not less 370 Relative elongation at break - at + 23 ° С,%, no more 6

Elongation at break - at -30 ° С,%, no more 7 Moisture absorption - when exposed to water for 24 hours at 20 ° C,%, no more 5 Flexural modulus, MPa, not more than 2500

Thus, the inventive rock sheet provides:

- high tensile, bending, torsion, impact resistance, which is especially important in the case of application for laying pipelines;

- fast and high-quality impregnation with a polymer composition, which shortens the technological cycle;

- reducing the number of required layers of the rock sheet during installation and optimizing the manufacturing process;

- ensuring strict compliance with the product reinforcement scheme specified in the design;

- the absence of knots of weaving threads on the surface of the product, which significantly improves the quality of the protective coating and eliminates damage.

Claims (2)

1. Rock sheet containing a hollow open cylinder formed by a flexible cloth, characterized in that the flexible cloth is made of at least one layer of multiaxial fabric based on fiberglass with a total thickness of not more than 5.5 mm, and a surface density of not more than 4, 5 kg / m ² , while the flexible panel is impregnated to the full thickness with a polymer composition based on PVC, acrylic or urea-formaldehyde resin, with a total polymer composition consumption of not more than 3.5 kg / m ² . 2. The rock sheet according to claim 1, characterized in that the flexible sheet is made of three layers of multiaxial fabric, while the two outer layers are made of fiberglass-based fabric, and the middle layer is of a nonwoven needle-punched synthetic fabric.