RU2746756C1 - Mechanical connection of pipes of main pipelines - Google Patents

Abstract

FIELD: oil and gas production, oil and gas processing, chemical, metallurgical industries.

SUBSTANCE: invention relates to the design of a device for connecting pipeline systems and can be used in connecting pipes of extended main pipelines for the transportation of water, oil, natural gas, other liquids and gases in the oil and gas production, oil and gas processing, chemical, metallurgical industries and other areas. The connection is carried out by tightening and uniform double-sided crimping of the conical parts of the pipe walls with the help of a conical connecting nipple sleeve and two spanning split multi-link tracks, as well as tightening pins, nuts and washers, which ensure its structural unity and strength. In this case, the sealing and impermeability of the connection is carried out on the inner conical surfaces of the pipes and the conical parts of the nipple sleeve.

EFFECT: invention provides a minimum assembly time, high accuracy and quality of connection of pipes of main pipelines even in difficult weather conditions on the ground, in trenches, on overpasses, in cramped tunnels and rooms, as well as under water.

1 cl, 4 dwg

Description

The present invention relates to a device for connecting pipeline systems and can be used in connecting pipes of main pipelines for transporting water, oil, natural gas, other liquids and gases in the oil and gas production, oil and gas processing, chemical, metallurgical industries and other fields.

There are numerous traditional methods of connecting large-diameter main pipes, mainly using butt welded joints, as well as flanged mechanical joints with pipe fittings, pumps and other equipment. But for the connection of main pipes by butt welding, complex and expensive equipment and a long process of the welding operation itself are required. At the same time, it is very problematic to perform in extreme temperature conditions high-quality welding of pipe joints, cleaning of internal reinforcements of welded seams and ensuring proper corrosion resistance of the welded joint zone during the subsequent operation of pipelines. In addition, the process of welding pipes of main pipes becomes much more difficult in bad weather in the field, in offshore laying and in difficult welding operations under water.

Also known is the closest analogue of the mechanical connection of pipes with outer tapered sections, one nipple sleeve, tightly adjacent with two tapered surfaces to the inner tapered surfaces of the end sections of the pipes by tightening them in the axial direction by means of flanges, bolts, nuts and washers used in a rigid coupling of the fuel line ( US 2985466 A, 23.05.1961). The structural difference of the tightening assembly of the specified connection consists in the need to install flanges on the end sections of pipes before expanding them, which limits the possibility of using such a low-tech connection for pipelines of large diameters up to 1500 mm and more. Another analogue of a mechanical flange pipe joint is also known, in which impermeability is ensured by crimping the end gasket by compressing the welded flange pipe stops by tightening multi-link split tracks, which are prefabricated plate half rings, and fasteners in the form of studs and nuts (US 2911239 A, 03.11.1959 ). The main structural difference of the specified connection is the use of a collapsible design of the tightening device instead of traditional welded bulky flanges to allow pipes to pass through small holes. The disadvantage of the connection is the low rigidity of the joint of the half rings and the unevenness of the compression of the end gasket. The specified connection is not applicable in pipeline connections requiring high reliability.

The objective of the invention is to create a universal, technologically advanced, reliable and durable device for mechanical connection of pipes of large diameters, with pre-formed and precisely machined tapered parts at the end sections of the pipes, providing accelerated laying of main pipelines without the use of butt welding of pipes. It is assumed that such a device must fulfill the following initial requirements:

- mechanical pipe connection, which is not inferior to the welded joint in terms of basic operational properties;

- preservation in the joint of a full-sized smooth flow section of pipes without constrictions, ledges and internal protruding parts;

- providing a simple and quick alignment of pipes when connecting them;

- wide range of permissible operating pressure up to 250 bar and more;

- unlimited range of pipe wall thicknesses;

- a wide range of external pipe diameters from 750 to 1500 mm and more;

- permissible range of temperatures exceeding the temperature of the pipeline;

- the service life of the connection, exceeding the service life of the pipeline;

- the possibility of reusing connection parts when replacing pipes;

- use of a universal joint for pipes made of carbon, high-alloy and stainless steel, as well as pipes made of reinforced plastic and metal-plastics.

The problem is solved by the fact that the pipe connection is carried out by a mechanical device due to squeezing and uniform two-sided crimping of the tapered parts of the pipe walls (1 and 6) using a tapered nipple sleeve (3) and two female, split, multi-link tracks of the original design (2 and 5) , as well as tightening studs (4), nuts (7) and washers (8), which provide structural integrity and strength of the connection, and the number and size of the studs depends on the diameter of the pipeline and the required strength of the connection.

In this case, the elongated pins are the axes of the track links and elastic rods, creating a constant squeezing of all tapered surfaces when the nuts are tightened. To ensure uniform compression of the joint, the inner surfaces of the track and outer surfaces of the pipes have the same taper. Sealing in the joint is carried out along the inner tapered surfaces of the pipes and the tapered surfaces of the nipple sleeve after they are pulled together and crimped, and impermeability is ensured by their tight fit due to the appropriate processing of the tapered surfaces.

For especially strong thick-walled metal pipes, their end tapered sections can be welded, with the removal of the reinforcement of the welded seam inside the pipe by stripping and grinding to the full flow area of the pipeline. In all other respects, the design of such a pipe connection is completely preserved unchanged, as for pipes with flared conical parts.

To carry out rigging work when laying a pipeline, to simplify the assembly of the connection or to ensure its dismantling, in the middle part of the nipple sleeve there is a transverse annular groove and longitudinal grooves located in a staggered manner.

An important circumstance is that, on the basis of the proposed mechanical pipe connection, an option with a face seal can be created, which will make it possible to connect to traditional flange connections of downhole pipelines, to existing pipe fittings and other equipment while maintaining all the above-listed initial requirements for a new type of connection.

Taking into account the uniqueness of the specified connection, it is proposed to give a name to the new type of connection - track mechanical connection of main pipes.

The basic construction of a mechanical track connection device for main pipes is shown in the attached figures:

- General view of the pipe connection in FIG. # 1;

- connection of pipes with flared conical parts in FIG. # 2;

- connection of pipes with welded tapered parts in FIG. Number 3;

- the connection of light pipes reinforced with plastic reinforced in FIG. No. 4.

The presented figures fully disclose the general idea of the design of the device, the proposed pipe connection, its peculiarity and technical novelty.

The proposed design of the device for track mechanical connection of pipes of main pipelines ensures the fulfillment of all the above-listed initial requirements, and the analysis of the possibility of its use gives the following obvious technological and operational advantages in comparison with the traditional connection of such pipelines by welding:

- ease of connection due to self-centering and tight fixation of pipes;

- fast, accurate and high-quality assembly of pipe connections;

- the possibility of multiple assembly and disassembly of the connection;

- the possibility of complete dismantling of the connection for repair or replacement of pipes;

- the ability to connect pipes made of dissimilar materials;

- connection of pipes with different wall thicknesses, while maintaining the flow area;

- the ability to create a high-strength one-piece pipe connection;

- complete safety of internal and external coatings of pipes after connection;

- high corrosion resistance of pipes in the joint;

- increasing the density of the connection with increasing pressure in the pipeline;

- visual convenience of monitoring the tightness of pipe connections;

- high productivity of assembly and testing of pipelines;

- protection from damage to the internal sealing surfaces of pipes during storage, transportation and assembly of pipelines in difficult conditions.

An important advantage of the proposed device design is that all connection parts are manufactured and fully assembled in stationary shop conditions. This will ensure the minimum assembly time, high accuracy and quality of pipe connections in difficult weather conditions in the open air, in trenches, on ramps, in confined tunnels and rooms, as well as under water. It is assumed that after the development of drawings, the manufacture of prototypes and all the necessary tests, clarification of the standard size range, the final selection of materials for the device parts, the development of the entire technological chain of processing mating conical surfaces, the assembly of the track mechanical connection and the installation of the pipeline, a new application with a potential Investor for registration of an international patent.

Claims (1)

Mechanical connection of pipes of main pipelines for pumping various liquids and gases, consisting of one nipple sleeve, tightly adhering with two conical surfaces to the inner conical surfaces of the pipes to be connected by tightening them, characterized in that the connection is equipped with two detachable multi-link tracks, uniformly covering and crimping the outer conical the surfaces of the pipes to be connected, with the possibility of tightening the tracks together in the axial direction of the pipes by means of pins passing through the links of the chains, nuts and washers.

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