RU2247278C2 - Permanent dielectric coupling joint - Google Patents

Abstract

FIELD: pipeline engineering.

SUBSTANCE: joint comprises two metallic branch pipes and ring made of dielectric material and interposed between the faces of branch pipes. The branch pipes have bells which are interconnected through insert by permanent dielectric adhesive joint from the inside and through metallic coupling by permanent dielectric locking adhesive joint on the outside.

EFFECT: enhanced reliability and prolonged service life.

4 cl, 1 dwg

Description

The invention relates to the field of pipeline transport, and in particular to the protection of pipelines from corrosion, and can be used to electrically disconnect pipelines into sections protected from corrosion by tread or cathodic protection methods.

Known electrical insulating flange connections (RF patents: No. 2076985, class F 16 L 23/02; No. 2162981, class F 16 L 25/02; No. 2174637, class F 16 L 23/03), which are very difficult to manufacture and have low reliability during operation, as they have a large number of parts made of dielectric material, negatively affecting the reliability of the connection. In addition, they cannot be used for underwater and underground pipelines because of the constant need to monitor the condition of the tightness of the connection, since during operation, the threaded joints of the flanges are weakened.

Known electrically insulated connection of pipelines (RF patent No. 2084745, class F 16 L 23/02) containing metal pipes with annular thickenings, which are made of pre-rolled profiles and are connected, for example, by welding with pipes made of pipe, while between the ends the nozzles facing each other, a protective ring is installed, and the annular portions of the nozzles are covered by a seal made in the form of an annular cuff of gas-tight material, and the nozzles are connected by a fiber-optic fastener of the composite material.

This design of an electrically insulated connection is laborious to manufacture, since it is necessary to connect the ring seals to the pipes by welding. And, in addition, the connection itself has low reliability during the construction and operation of the pipeline, since the fastener is made of fibrous composite material, which has low crack resistance, as the authors of this invention refer to the book “Structural plastics”, M. Chemistry, 1979 Indeed, the experience of operating underground oil pipelines mounted from fiberglass pipes showed that they break down during the construction or operation of the pipeline, since they kink do not work. So, for example, when the soil freezes, they often break.

A current-insulating connection for a pipeline is known (RF patent No. 2174638, class F 16 L 25/03), containing two metal nozzles electrically isolated from each other by a fiberglass ring, a coil of dielectric material is placed inside the machined part of the nozzles, which are connected to the nozzles by glue and thread made at the ends of the coil, and the nozzles are connected by a fiberglass pipe made by winding on the nozzles (prototype).

This connection has the same disadvantages as the previous one, that is, low reliability during the construction and operation of the pipeline. As experience shows, there have been cases when they have already failed in the process of loading and unloading.

The objective of the invention is to increase the reliability and durability of an electrically insulating compound.

The problem is achieved in that in a one-piece electrically insulating sleeve connection containing two metal nozzles, between the ends of which a ring of dielectric material is placed, the nozzles are connected from the inside by a dielectric adhesive joint, and from the outside by a dielectric adhesive coupling, where what is new at the ends of the nozzles sockets are made in which the liner is installed, and outside the nozzles are connected through a dielectric material with a metal coupling with a locking adhesive Kim compound. An anticorrosion coating of dielectric material may be applied to the inner surface of the nozzles. The adhesive joints of the liner and the coupling with the nozzles can be reinforced with a fabric of dielectric material. An anti-corrosion coating of dielectric material is applied to the outer surface of the compound. The connection of the metal nozzles from the outside with a metal coupling with a one-piece dielectric lock adhesive-mechanical connection allows to increase the reliability and durability of the connection due to the contact surfaces of the nozzles and the coupling being connected by a shear adhesive joint, a mechanical joint due to friction forces, and simultaneously with the formation of the lock joint between the ends of the nozzles and the clutch working on the cut. The use of an adhesive composition of a dielectric material allows you to electrically disconnect the nozzles and the coupling. This design of one-piece electrically insulating coupling joints is reliable and durable and devoid of the disadvantages that are found in other designs of electrically insulating joints. The implementation of the sockets at the inner ends of the metal pipes allows you to save the internal cross section of the insulating connection and at the same time they serve to obtain a lock connection with the coupling. Reinforcing the adhesive layer with a fabric made of dielectric material improves the operational properties of the electrically insulating compound and simplifies the manufacturing technology by reducing the likelihood of direct contact between the liner and the sleeve with metal pipes. Applying a coating of dielectric material on the outer surface of the joint allows protecting the joint parts from corrosion and preserving the electrical insulating properties of the permanent electrical insulating sleeve joint. All these distinguishing features provide additional technical results that can further improve the reliability and durability of one-piece electrically insulating sleeve connections during transportation, installation and operation.

The drawing shows a General view of the proposed design of an integral coupling connection.

The one-piece electrically insulating sleeve connection contains metal pipes 1 in which the pipes 2 are made, a ring 3 of dielectric material, an insert 4, an adhesive layer 5 of dielectric material reinforced with a fabric of dielectric material, a metal sleeve 6, an adhesive layer 7 of dielectric material reinforced with a fabric of dielectric material, the lock connection 8, the inner coating 9, deposited from a dielectric material, the insulation 10 also from the dielectric material and the chamfer 11 for welding.

The manufacture of the claimed design of a permanent electrically insulating sleeve connection is carried out in the following sequence.

At the ends of the metal pipes 1 on the one hand make sockets 2, and on the other - chamfers 11 for welding. An adhesive layer 5 of dielectric material is applied to the liner 4, which is reinforced with a fabric of dielectric material. On the liner 4 install a ring 3 of dielectric material. Next, the liner 4 is pressed into the sockets 2 of the metal nozzles 1, while the ring 3 is installed between the ends of the nozzles 1. Between the liner 4 and the inner surface of the sockets 2 of the nozzles 1 is formed gluomechanical connection.

An adhesive layer 7 reinforced with a fabric is applied to the outer surface of the nozzles 1, a sleeve 6 is installed so that it equally grips the nozzles 1. The sleeve 6 has a greater length than the total length of the nozzles 2 of the nozzles 1 and the ring 3. Connect the sleeve 6 to the nozzles 1 by reducing the coupling 6 by means of a hydraulic press equipped with a die. At the same time, the ends of the coupling 6 are reduced by a large amount, at which a lock connection 8 is formed between the ends of the coupling 6 and the outer surface of the nozzles 1. When reducing between the contact surfaces of the liner 4 of the nozzles 1 and the coupling 6, a mechanical connection is formed, which works due to friction forces, and at the same time, pressure is created to glue the same surfaces. A coating 9 of a dielectric material is applied to the inner surface of a permanent electrically insulating sleeve connection, and an insulation 10 of a dielectric material is applied to the outer surface.

One-piece electrically insulating sleeve connection is assembled with the pipeline using electric arc welding.

Used Books

1. RF patent No. 2076985, cl. 6 F 16 L 23/02. Electrical insulating flange connection (Gamayunov G.K., Pronin V.P.). Application No. 93042082/06 of 08.24.1993, published on 04.10.1997, Bull. No. 10.

2. RF patent No. 2084745, class. 6 F 16 L 23/02. An electrically insulated connection of pipelines (Semenyuga V.V., Usoshin V.A., etc.). Application No. 95118231/06 of 10.26.1995, published on 07.20.1997, Bull. No. 20.

3. RF patent №2162981, cl. 7 F 16 L 25/02. High pressure flange connection with dielectric pipe connector (Bayazitov Z.A., Ibragimov N.G., Magalimov A.A.). Application No. 99101595/06 dated January 25, 1999, published on October 27, 2000, Bull. No. 30.

4. RF patent No. 2174637, cl. 7 F 16 L 25/02. Dielectric flange connection of the pipeline (Ibragimov N.G., Zakirov A.F., Paramonov Yu.N., Magalimov A.A., Bayazitov Z.A.). Application No.2002202028 / 06 dated 08/17/2000, published on 10/10/2001, Bull. No. 28.

5. RF patent No. 2174638, cl. 7 F 16 L 25/02. Current-insulating connection for the pipeline (Ibragimov N.G., Zakirov A.F., Paramonov Yu.N., Magalimov A.A., Bayazitov Z.A., Rakhmatullin D.K.). Application No.2002202029 / 06 of 08/17/2000, published on 10/10/2001, Bull. No. 28.

Claims (4)

1. One-piece electrically insulating sleeve connection containing two metal nozzles, between the ends of which a ring of dielectric material is placed, the nozzles are connected from the inside by a dielectric adhesive joint, and outside by a dielectric adhesive coupling, characterized in that the ends of the nozzles are made with sockets in which the insert is installed and outside the nozzles are connected through a dielectric material by a metal coupling with an integral locking adhesive-mechanical connection. 2. The compound according to claim 1, characterized in that on the inner surface of the nozzles applied anti-corrosion coating of dielectric material. 3. The compound according to any one of claims 1 and 2, characterized in that the adhesive layer of the joints of the liner and the coupling with the nozzles is reinforced with a fabric of dielectric material. 4. The compound according to any one of claims 1 to 3, characterized in that its outer surface is protected from corrosion by a coating of a dielectric material.