RU99580U1 - BALLAST COATED PIPE - Google Patents

Abstract

 1. A ballast-coated pipe comprising a central pipe, a sheath mounted coaxially with the central pipe to form an annular space having an inner diameter larger than the outer diameter of the central pipe, a support-guide device consisting of centralizers, and a ballast material, characterized in that a layer of polyurethane foam is applied between the central tube and the ballast material, on which centralizers are distributed and fixed, a reinforcing frame with clamps is located inside the ballast material, hold the reinforcing cage on a layer of polyurethane foam, while the reinforcing cage has at least four longitudinal reinforcement, on which the transverse reinforcement is helically wound with equal pitch, the longitudinal and transverse reinforcement are connected using a knitting wire and / or welding, and as ballast material used concrete mix. ! 2. The ballast-coated pipe according to claim 1, characterized in that the shell is made of a metal polymer. ! 3. The ballast-coated pipe according to claim 1, characterized in that the shell is made of metal. ! 4. The ballast-coated pipe according to claim 1, characterized in that the shell is made of polymer. ! 5. The ballast-coated pipe according to claim 1, characterized in that the central pipe has a protective layer of polyethylene.

Description

The inventive device relates to pipeline technology, namely, pipes with ballast coating, used when laying pipelines along the bottom of reservoirs.

A known pipe described in the invention for a method consisting of a central steel pipe, a pipe sheath made of polyethylene, a pipe sheath is installed coaxially with the central pipe with a gap and forms an annular annular space. The central pipe has an anti-corrosion coating. Support centering rings are mounted and fixed on the central tube evenly along its length. Each supporting centering ring is made integral and contains a flexible steel tape, the ends of which are interconnected by a lock with the formation of a ring. Along the circumference of the ring, centering protrusions of rectangular shape made of hard polyethylene are evenly distributed. The annular space between the central pipe and the polyethylene pipe is filled with cement-sand mortar (Patent RU No. 2257503 of 10.22.2003).

A disadvantage of the known pipe is that when the central pipe with supporting centering rings is inserted into the polyethylene pipe, which, as a rule, has deviations from the regular cylindrical shape, significant pressure arises on the surfaces of the centering protrusions in contact with the inner surface of the polyethylene pipe, and, accordingly significant frictional force arises, creating a tilting moment on the centering protrusions, which leads to difficulty in movement and causes local buckling of the shell Even her break.

In addition, the rectangular centering protrusions, when filling the annular space with concrete, create significant hydraulic resistance to the movement of a viscous weighting cement-sand or concrete mixture, and, as a result, a significant pressure drop in the mixture in front of the protrusions and behind the protrusions, and the occurrence of a tipping moment on the protrusions, capable of cause them to tip over with a possible break of the flexible steel strip, which will lead to marriage.

Closest to the claimed technical solution is the design of the pipe combined with a ballast coating. A pipe combined with a ballast coating consists of a central pipe that conducts the substance in a gaseous or liquid state and a shell installed coaxially with the central pipe to form an annular space. The inner diameter of the shell is greater than the outer diameter of the central pipe, and the length of the shell than the length of the central pipe. The central pipe is equipped with a supporting-guide device, which consists of centralizers distributed and fixed on the outer surface of the central pipe. Centralizers have chamfers that are located on surfaces in contact with the inner surface of the shell. An annular space fills the ballast material. The shell is a spiral-wound galvanized steel strip with protruding inward seams. The shell on the outer surface has a protective coating (Patent RU No. 2317469 from 10.20.2006).

The disadvantage of this pipe is its low strength and low frost resistance. If the protective coating is damaged in the pipe laid on the bottom of the reservoir, it is destroyed, since the pipe shell is spiral-wound from galvanized steel tape and has seams.

The technical result achieved in the inventive pipe with a ballast coating, is to increase the strength, frost resistance and durability of the device. In addition, bending strength is increased and the scope of application is expanding, due to the possibility of use in the Far North.

The technical result is achieved in that the ballast-coated pipe comprises a central pipe, a sheath mounted coaxially with the central pipe to form an annular space, a ballast material and a support-guide device. The central shell has an inner diameter larger than the outer diameter of the central pipe. The supporting-guide device consists of centralizers. A layer of polyurethane foam is applied between the central tube and the ballast material. Centralizers are distributed and fixed on a layer of polyurethane foam. A reinforcing cage is located inside the ballast material with retainers holding the reinforcing cage on the layer of polyurethane foam and centralizers. At the same time, the reinforcing cage has at least four longitudinal reinforcement, onto which the transverse reinforcement is wound in a spiral with equal pitch. Longitudinal and transverse reinforcement is connected by knitting wire and / or welding. As a ballast material used concrete mixture.

In the particular case, the shell may be made of a metal polymer.

In the particular case, the pipe may have a protective layer of polyethylene.

In the particular case, the shell may be made of metal.

In the particular case, the shell may be made of polymer.

Figure 1 shows a longitudinal section of a ballast-coated pipe;

figure 2 is a cross section of a pipe with a ballast coating;

figure 3 - design of the reinforcing cage.

The ballast-coated pipe (FIGS. 1, 2) comprises a central pipe 1, a support-guide device consisting of centralizers 2. Moreover, a protective layer of polyethylene (not shown) can be applied to the central pipe 1. Between the central tube 1 and the ballast material 3, a layer 4 of polyurethane foam is applied. Centralizers 2 are distributed and fixed on a layer 4 of polyurethane foam. The reinforcing cage 5 is mounted on the layer 4 of polyurethane foam using clamps 6 and is located inside the ballast material 3, on the surface of which the sheath 7 is formed. The reinforcing cage 5 (Fig. 3) consists of longitudinal reinforcement 8, onto which the transverse reinforcement is wound with an equal pitch 9.

The assembly of the inventive ballast-coated pipe is as follows.

In the manufacture of the central pipe 1, a three-layer polyethylene coating is applied to its surface, which is peeled off from the ends of the central pipe. Then, a layer 4 of polyurethane foam is applied to the central pipe 1. Layer 4 polyurethane foam can be applied as follows. A sheath pipe made of polyethylene (not shown in the figures), which has an opening for supplying polyurethane foam, is coaxially mounted on the central pipe 1. The polyethylene sheath is sealed by installing plugs at the ends of the pipe with the air holes up, leaving pipe outlets of the order of 15-25 cm. Then, polyurethane foam is poured into the annulus through the plug hole from the raised end of the pipe (the pipe is installed with a slope of up to 5 °) . In the process of foaming polyurethane foam, the annular space is filled in the direction from the bottom up with the simultaneous displacement of air from it through the air holes in the upper plug.

After pumping under the casing pipe and hardening the polyurethane foam, the casing pipe can be removed, or it can be left to protect against mechanical damage when centralizers 2 and reinforcing cage 5 are installed on layer 4 of polyurethane foam.

Polyurethane foam has a very low coefficient of thermal conductivity - 0.05 W / (m * K), which with a layer thickness of 80 mm, gives a heat transfer resistance of 1.6 (m * K) / W. Polyurethane foam is very resistant to external factors, it does not collapse under the influence of ultraviolet radiation, salts, acids up to 10% and alkalis.

After polymerization of polyurethane foam, the central pipe 1 is fixed to the assembly stand (not shown in the drawing) and the first plug with a rubber rubber ring is installed on it. The reinforcing cage 5 is mounted on a separate stand of longitudinal reinforcement 8, onto which the transverse reinforcement 9 is helically wound with equal pitch. The longitudinal 8 and transverse 9 reinforcement are connected using a knitting wire and / or welding. The mounted reinforcing cage 5 is secured to the polyurethane foam layer 4 using clamps 6. Then centralizers are assembled 2. A shell 7 is formed on top of the reinforcing cage 5. The shell 7 can have a different configuration, that is, depending on the device of the centralizers, the cross-section of the shell can be made in the form square, rectangle, circle or ellipse. The shell 7 can be made of various materials (metal, metal polymer, polymer). The shell material 7 is selected from the conditions in which the ballast-coated pipe will be operated. Then install the second plug with a rubber sealing ring, while one of the plugs has a neck for pumping concrete mixture. The assembled structure is removed from the assembly stand and laid in a tool tray. Ballast material (concrete mixture) 3 is pumped through the neck of the plug using a concrete pump. The setting of the ballast material 3 occurs in 3-3.5 hours. Then, the plugs are removed and the structure is left for 10-12 hours at a temperature of + 15- + 20 ° C to set the strength of the ballast material 5 to 5 MPa. A set of strength of the ballast material 3 to 20 MPa is carried out after laying the ballast-coated pipe on a sand cushion.

The claimed pipe with a ballast coating is strong, frost-resistant and durable. It has increased bending strength and can be used in the construction of underwater pipelines for laying them in various climatic conditions.

Claims (5)

1. A ballast-coated pipe comprising a central pipe, a sheath mounted coaxially with the central pipe to form an annular space having an inner diameter larger than the outer diameter of the central pipe, a support-guide device consisting of centralizers, and a ballast material, characterized in that a layer of polyurethane foam is applied between the central tube and the ballast material, on which centralizers are distributed and fixed, a reinforcing frame with clamps is located inside the ballast material, hold the reinforcing cage on a layer of polyurethane foam, while the reinforcing cage has at least four longitudinal reinforcement, on which the transverse reinforcement is helically wound with equal pitch, the longitudinal and transverse reinforcement are connected using a knitting wire and / or welding, and as ballast material used concrete mix. 2. The ballast-coated pipe according to claim 1, characterized in that the shell is made of a metal polymer. 3. The ballast-coated pipe according to claim 1, characterized in that the shell is made of metal. 4. The ballast-coated pipe according to claim 1, characterized in that the shell is made of polymer. 5. The ballast-coated pipe according to claim 1, characterized in that the central pipe has a protective layer of polyethylene.