Vol. 7 ¹ 4, 2017 p 54-61

Pages

Article name, authors, abstract and keyword

54-61

Development of repair components for selective repair of the pipelines

Nikolay G. Goncharov a, Aleksey A. Yushin a, Artem V. Sudnik a

a Pipeline Transport Institute, LLC (Transneft R&D, LLC), 47a, Sevastopolskiy prospect, Moscow, 117186, Russian Federation

https://doi.org/10.28999/2541-9595-2017-7-4-54-61

Abstract: Introduction. The paper reviews the topical issues of selective repair of defective sections of oil and oil products pipelines with the help of repair components - split and female tees. The analysis of split tees use is provided, the peculiarities of installation and welding works, as well as field research results are stated.
State of the issue. The key element in arrangement of reliability and safety of oil transportation to consumers is timely technical maintenance and repair of the pipelines. Despite of insulation and electrochemical protection of the pipelines, individual sections of long-term operated pipelines have external and internal damages, both corrosive and mechanical, and defects of electric arc welding of girth and longitudinal welds, which are considered hazardous under contemporary quality control standards. Safety of Major Pipelines (MP) operation and their reliable uninterrupted operation are secured by relevant activities both at the design stage and during MP operation. Among operating activities the arrangement of periodical technical diagnostics of MP elements state and elimination of unacceptable defects are of great importance. A considerable part of detected defects is unacceptable and requires elimination. One of the directions of repair technologies development is the development of repair elements which allow to perform the repair both on operating and on shutdown pipeline. A special attention in this connection must be paid to the split tees, which are used in cases when usage of other repair elements or methods is ineffective or impossible.
The challenge. Until quite recently the split tees were used for repair of the pipelines with the diameter 530–1220 mm, there were no repair elements for pipes with the diameter 219–426 mm. The paper provides technical solutions for repair of the small diameter pipelines.
Testing methods. Here we present the results of static strength and durability testing of repair elements by cyclic loading at maximum allowable loads under operating conditions on specialized stand and detailed testing methods are described.
Testing results. Stand testing have indicated that the tested specimen were not destroyed at loads simulating the maximum pipeline load under operating conditions.
Conclusions. Evaluation of research results has indicated that the service life of the developed repair elements can come up to min. 30 years, which makes it reasonable to use them for repair works execution on small diameter pipelines.

Keywords: split tee, welds, major pipelines, welding, pipe, heat-affected area, thermal cycle of welding, mechanical properties

Reference for citing:
Goncharov N. G., Yushin A.A., Sudnik A.V. Development of repair components for selective repair of the pipelines. Naukatekhnol. truboprov. transp. neftiinefteprod. = Science & Technologies: Oil and Oil Products Pipeline Transportation. 2017; 4(7):54–61.

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