Use of the Threaded Plugs when Repairing Main Pipelines


Annotation:

To ensure the reliability and industrial safety of the main pipelines, their timely diagnosis and repair of detected defects are necessary. The design features of the threaded sealing plugs are considered in the article, and the technology is proposed for conducting non-destructive quality control of their welded joints.
In practice, pipeline repair showed that the installation of sealing plugs is carried out in those cases when the use of other repair parts (steel and fiberglass couplings, split tees) is impossible or inefficient.
Among many other repair technologies that allow to restore bearing capacity of the pipelines that have local through defects to the design level, the repair utilizing sealing plugs is the simplest and most cost-effective appropriate technology. It is the least expensive and does not require cutting out the defective section of the pipe (pipe spool or pipe section) and cutting in the new pipe spool or pipe section.
Practical experience in pipeline repair with through defects shows that the defects with up to 40 mm in diameter can be eliminated with the help of sealing plugs with mandatory subsequent quality control after their installation. Despite the relatively small sizes of the welded joints that are formed during welding when installing plugs, their quality control causes significant difficulties. Thus, the X-ray control must be carried out according to through the double-wall scheme, which is not always possible because two-way access is required to the object of control or to the problem area with the need to remove the transported product. Ultrasonic testing using the classic echo method has significant limitations due to the complexity of determining the height of the defect on the amplitude basis.
The visual and measuring control and the dye penetration inspection are insufficient. The method using ultrasonic diffraction-time method is proposed, which allows to perform quality control of the welded joints when repairing through holes in the pipe with the help of plugs.
 

References:
  1. Goncharov N.G., Gobarev L.A., Kolesnikov O.I., Lopatin E.V., Romanova I.A. Main pipelines linear part repair by means of cutting flanged tees. Truboprovodnyy transport: teoriya i praktika = Pipeline transport: theory and practice. 2010. № 4. pp. 28–30. (In Russ.).
  2. Mazel A.G., Gobarev L.A., Nagornov K.M., Rybakov A.I. Welded sokets for pipelines repair. Gazovaya promyshlennost = Gas Industry. 1996. № 9–10. pp. 55–57. (In Russ.).
  3. Malik M.Y. Contrasting Welding Techniques Used on Pipelines and Refinery Piping: Uphill Versus Downhill. Pipeline & Gas Journal. 2012. Vol. 239. № 1.
  4. Neganov D.A., Goncharov N.G., Yushin A.A., Kolesnikov O.I. Special structures for pipelines selective repair. Neftyanoe khozyaystvo = Oil Industry. 2018. № 7. pp. 120–123. (In Russ.). DOI: 10.24887/0028-2448-2018-7-120-123 
  5. Aleshin N.P., Chernyshev G.G. Welding. Cutting. Control: Reference book: in 2 volumes. Vol. 1. Мoscow: Mashinostroenie, 2004. 624 p. Available at: https://ru.b-ok.cc/ireader/749080 (accessed: December 23, 2019). (In Russ.).
  6. Goncharov N.G., Yushin A.A., Kolesnikov O.I., Sudnik A.V. Elimination of pipeline defects using steel sealing caps. Nauka i tekhnologii truboprovodnogo transporta nefti i nefteproduktov = Science & Technologies: Oil and Oil Products Pipeline Transportation. 2019. Vol. 9. № 5. pp. 538–544. (In Russ.). DOI: 10.28999/2541-9595-2019-9-5-538-544
  7. Zaikin I.A., Aleshin Yu.V., Lisanov M.V., Agapov A.A., Sofyin A.S., Sumskoy S.I. Investigation of the Effect of Process Parameters of the Main Pipelines on the Accident Risk Indices for Safe Distances Substantiation. Bezopasnost truda v promyshlennosti = Occupational Safety in Industry. 2018. № 12. pp. 71–78. (In Russ.). DOI: 10.24000/0409-2961-2018-12-71-78
  8. Makhutov N.A., Fridlyand Ya.M., Raspopov A.A., Lisanov M.V. Development of Approaches to Solving the Problems of Ensuring Strength, Service Life and Safety of the Trunk Oil Transportation. Bezopasnost truda v promyshlennosti = Occupational Safety in Industry. 2019. № 9. pp. 7–14. (In Russ.). DOI: 10.24000/0409-2961-2019-9-7-14
  9. Ginzel E. Ultrasonic Time of Flight Diffraction. Waterloo: Eclipse Scientific, 2014. 260 p.
  10. Ginzel E., Honarvar F., Yaghootian A. A Study of Time-of-Flight Diffraction Technique Using Photoelastic Visualisation. The 2nd International Conference on Technical Inspection and NDT (TINDT2008). Available at: https://pdfs.semanticscholar.org/7a8c/5d4c21252abf188ea2fdffc6d49da17f0174.pdf?_ga=2.78766812.91689381.1580458867-1533651216.1580458867 (accessed: December 23, 2019).
  11. Sergeev S.S., Prokopenko E.N., Sergeeva O.S. Acoustic control devices and methods. Mogilev: Izd-vo GU VPO «Belorussko-Rossiyskiy universitet», 2014. 32 p. Available at: http://e.biblio.bru.by/bitstream/handle/1212121212/5712/_80_%28206%29_.pdf?sequence=1&isAllowed=y (accessed: December 23, 2019). (In Russ.).
  12. Carter P. Experience with the Time-of-flight Diffraction Technique and an accompanying Portable and Versatile Ultrasonic Digital Recording System. British Journal of Non-Destructive Testing. Sep. 1984. pp. 354–361.
DOI: 10.24000/0409-2961-2020-3-65-70
Year: 2020
Issue num: March
Keywords : trunk pipeline welding welded joint ultrasonic control flaw flaw detector sealing plug pipe repair structures diffraction-time method
Authors: