RU2742671C1 - Mechanical connection of large diameter pipes - Google Patents

Abstract

FIELD: gas and oil industry.

SUBSTANCE: invention relates to the design of a device for connecting pipeline systems and can be used in connecting pipes of various pipelines for transporting water, oil, natural gas, and other liquids and gases. The pipe connection is carried out by a mechanical device by squeezing and uniform double-sided crimping of the tapered parts of the pipe walls (1 and 6) using a tapered nipple sleeve (3), two female, split, multi-link plate chains (2) and (5), as well as tightening pins (4), nuts (7) and washers (8), which provide structural integrity and strength of the connection, and the number and size of 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 chain links and elastic rods, creating a constant squeezing of all tapered surfaces when the nuts are tightened. To ensure uniform reduction of the joint, the inner surfaces of the chains and the 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.

EFFECT: better impermeability due to more efficient pipeline connection.

1 cl, 4 dwg

Description

The proposed invention relates to a device for mechanical connection of pipeline systems and can be used in the connection of pipes of various large-diameter pipelines for transporting water, oil, natural gas, other liquids and gases in the oil and gas production, oil and gas processing, chemical, metallurgical industry, shipbuilding, industrial construction and other areas.

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

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 clamping unit 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 800 mm or more.

The objective of the invention is to create a universal technological device for a reliable and durable mechanical connection of pipes of large diameter, with pre-formed tapered parts at the end sections of the pipes, providing accelerated laying of 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 pipe outer diameters from 200 to 800 mm and more;

- permissible range of temperatures exceeding the pipeline temperature;

- 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, non-ferrous, aluminum and titanium alloys, as well as pipes made of reinforced plastic and metal-reinforced plastics.

The problem is solved by the fact that the pipe connection is carried out by a mechanical device due to squeezing and uniform double-sided crimping of the tapered parts of the pipe walls (1 and 6) using a tapered nipple sleeve (3), two covering, split, multi-link plate chains (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 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 chain links and elastic rods, creating a constant squeezing of all tapered surfaces when the nuts are tightened. To ensure uniform reduction of the joint, the inner surfaces of the chains and the 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 reinforcement of welded seams 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 without changes, 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 checkerboard pattern.

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.

Given the uniqueness of the specified connection, it is proposed to give a name to the new type of connection - a mechanical chain connection of large diameter pipes.

The basic design of a mechanical chain linking device for large diameter pipes is shown in the accompanying figures:

- General view of the pipe connection in FIG. one;

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

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

- connection of light pipes reinforced with plastic reinforced in FIG. 4.

The presented figures 1-4 fully disclose the general idea of the device design, the proposed pipe connection, its peculiarity and technical novelty.

The proposed design of the device for the chain mechanical connection of large-diameter pipes ensures that all the above-listed initial requirements are met, and the analysis of the possibility of its use gives the following obvious technological and operational advantages over the traditional welding of such pipelines:

- 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 mounting and dismounting 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 pipe coatings 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 their 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 completely assembled in stationary shop conditions. This will ensure the minimum assembly time, high accuracy and quality of pipe connections in difficult weather conditions in trenches, on racks, in confined tunnels and ship compartments, 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 of mating conical surfaces, the assembly of the chain mechanical connection and the installation of the pipeline, a new application with a potential An investor for an international patent.

Claims (1)

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

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