RU2131949C1 - Process of electrochemical protection of metal pipe-line against corrosion - Google Patents

Abstract

FIELD: anti-corrosion protection of pipe-lines. SUBSTANCE: two lengths of pipe made from same material as pipe-line are used as current-insulating inserts. Adjacent ends of lengths are insulated one from another by dielectric material and are linked by means of permanent coupling joint. EFFECT: improved electrochemical protection and decreased expenses. 3 dwg

Description

 The invention relates to the field of electrochemical corrosion protection of pipeline transport and can be used to electrically disconnect pipelines into sections protected from corrosion by electrochemical methods.

 There is a method of electrochemical protection of a metal pipeline, including the electrical separation of the protected area from the main pipeline by dielectric inserts made in the form of flanges with dielectric gaskets between them, and supplying a protection current to the separated area (Protection of metal structures from underground corrosion: Reference. / I.V. Strizhevsky et al., Moscow: Nedra, 1981, p. 217). The disadvantage of this method is that when implementing this method, significant material costs arise during the operation of wells in which the flanges are located.

 Closest to the proposed is a method of electrochemical protection of a metal pipeline (RF patent N 2095473, IPC 6 C 23 F 13/00, 1977), which includes electrical separation of the pipeline with insulating inserts and supplying an electric protection potential to it. This method as current-insulating inserts suggests the use of segments of multilayer flexible non-conductive pipes.

 The disadvantages of this method are: the high cost of the sleeves; complex technological operations in preparing the ends of the sleeves for welding; the lack of the necessary assortment and a large shortage of flexible hoses in terms of choosing them for the corresponding diameter, especially for large diameter pipelines; sealing of the connecting elements at the ends of the sleeves requires careful tightness control.

 The objective of the invention is to improve electrochemical protection and reduce material costs. The task is achieved in that two pieces of pipe made of the same material as the pipeline, the adjacent ends of which are insulated from each other by a dielectric material and connected by an integral coupling, are used as current insulating inserts.

 Analysis of known similar solutions allows us to conclude that there are no signs in them that are similar to differing features in the claimed method, that is, on the compliance of the proposed solutions with the criteria of "significant differences" and "novelty."

 In FIG. 1, 2 and 3 depict variants of current-insulating inserts made by the proposed method of electrochemical protection of a metal pipeline from corrosion.

 The method is as follows (figure 1). A dielectric material 2 is placed at the ends of two pipe sections 1 made of the same material as the pipeline, and the ends of the pipe sections 1 are insulated with a gasket 3 of dielectric material and the insulated ends of the pipe sections 1 are connected with a one-piece sealed coupling joint, crimped in the radial direction of the coupling 4. The ends of the pipe sections 1 can be insulated by placing a dielectric strip 5 having a T-shape. And also the insulation of the ends of the pipe segments 1 can be carried out by coating 6 on the inner surface of the coupling 4 (Fig. 3). Current-insulating inserts are manufactured both in the factory and directly in the installation environment. And the installation of current-insulating inserts is carried out by attaching them to the cut section of the pipeline using electric arc welding. After the test, the dug section of the pipeline is buried. A calculated current of electrochemical protection from a typical cathode station is supplied to an electrically disconnected section of the pipeline.

 Technical appraisal and economic advantages of the proposed method lie in the absence of current-insulating inserts, in the low cost of materials and the technology of their manufacture.

Used Books:
1. RF patent N 2095473, C 23 F 13/00, 10.11.97.

 2. Strizhevsky I.V. and others. Protection of metal structures from underground corrosion. -M .: Nedra, 1981.

Claims (1)

 A method of electrochemical protection of a metal pipeline from corrosion, comprising electrically insulating the protected section from the main pipeline with current insulating inserts and supplying an electric protection potential to it, characterized in that two pipe sections made from the same material as the pipeline are used as current insulating inserts the ends of which are insulated from each other by a dielectric material and are connected by an integral coupling connection.

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