The Paton Welding Journal, 2014, №05



2014 №05 (06)

DOI of Article 10.15407/tpwj2014.05.07

2014 №05 (08)

---

The Paton Welding Journal, 2014, #5, 40-47 pages  

DEVELOPMENT OF TECHNOLOGIES OF REPAIR BY ARC WELDING OF OPERATING MAIN PIPELINES IN UKRAINE

V.S. BUT and O.I. OLEJNIK

E.O. Paton Electric Welding Institute, NASU. 11 Bozhenko Str., 03680, Kiev, Ukraine. E-mail: office@paton.kiev.ua
 
 
Abstract
In order to lower material-financial and ecological losses inherent to classical method of main pipeline repair, associated with their stopping, methods allowing main lines to be repaired without taking them out of service, are applied worldwide. The paper deals with the directions of development at PWI of technologies of restoring the load-carrying capacity of defective sections of the main pipelines under pressure with arc welding application. Analysis of the features of arc welding application on pipelines under pressure has been performed and ways to eliminate the unfavourable factors have been determined. Influence of welding heat on strength characteristics of pipe metal is shown, and safe conditions of welding-up corrosion defects are established, depending on thermophysical properties of the transported product and internal pressure magnitude. The paper presents an original design-technological approach to performance of repair operations with arc welding application, which is implemented on operating mail pipelines of Ukraine. Experimental-theoretical assessment of the advantages of application of overlap-butt welded joints over traditional joints with fillet welds is given. Results of investigations by polarization-optical method of stress concentration factors in the points of deposited metal transition to base metal are presented for various kinds of loading of simulation samples. Application of overlap-butt joints allows expansion of heat input range in arc welding; controlling the dimensions, structure and properties of HAZ metal; lowering concentration in the points of circumferential weld transition to the pipeline and thus improving the fatigue limit of welded joints of reinforcing structures at repeated static load. Normative-technical documents have been developed and introduced, which specify repair of the main pipelines under pressure with application of arc welding, and cases of practical application of the most effective design solutions are shown. 23 Ref., 10 Figures, 1 Table.
 
 
Keywords: main pipelines, arc welding, overlap-butt joints, pressure, safe welding conditions, heat input, strength characteristics, stress concentration factor, reinforcing structural elements, fatigue limit
 
 
Received:                28.01.14
Published:               28.05.14
 
 
References
1. Bruce, W.A., Mishier, H.D., Kiefner, J.F. (1993) Repair of pipelines by direct deposition of weld metal. AGA Pipeline Res. Com. Project PR-185-9110. Edisson Weld. Inst.
2. But, V.S., Gretsky, Yu.Ya. (1997) On problem of joining of branchpipes to main pipelines in service conditions. Avtomatich. Svarka, 6, 25-33.
3. But, V.S., Gretskii, Yu.A. (2001) Repair of the main pipelines under pressure using arc welding. In: Proc. of Int. Conf. on Pipeline Repairs (Australia, 5-6 March, 2001).
4. Makhnenko, V.I., But, V.S., Kozlitina, S.S. et al. (2010) Risk of fracture of pressurised main pipeline with defects of the type of wall thinning during repair. The Paton Welding J., 1, 7-10.
5. But, V.S. (1991) Joining of branchpipes to main oil pipelines under pressure using arc welding. In: Petrol. Industry. Series Transport and oil storing. Moscow: VNIIOENG.
6. But, V.S., Rozgonyuk, V.V., Gretsky, Yu.Ya. et al. (2001) Validation of new approach to performance of welding operations on pipelines under pressure. Naft. i Gaz. Promyslovist, 4, 33-39.
7. (2007) ASME B31.8: Gas transmission and distribution piping system. Amer. Soc. of Mech. Eng.
8. Hrivnak, I. (1984) Weldability of steels. Moscow: Mashinostroenie.
9. (2007) CSA Z662-07: Oil and gas pipeline system. Canadian Stand. Assoc.
10. (2006) BS EN ISO 16708: Petroleum and natural gas industrials. Pipeline transportation systems. Reliability-based limit state methods.
11. Phelps, B., Cossie, B.A., Evans, N.H. (1986) Welding onto live natural gas pipelines. J. Metal Construction, 8, 350-354.
12. Kiefner, J.F., Maxey, W.A. (1989) Test validate pipeline sleeve repair technique. Oil and Gas J., 8, 47-52.
13. Korolkov, P.M. (1996) Heat treatment of pipeline welded joints in field conditions. Montazhn. i Spets. Raboty v Stroitelsve, 11/12, 21-24.
14. Bekker, M.V., But, V.S., Govdyak, R.M. et al. (2008) Repair of main pipelines under pressure. Kyiv: Kyj.
15. Dobrushin, L.D. (1981) Development and investigation of the technology of welding branchpipes of main gas pipelines under pressure using explosion energy: Syn. of Thesis for Cand. of Techn. Sci. Degree. Kiev.
16. But, V.S., Gretsky, Yu.Ya., Drogomiretsky, M.M. et al. (1998) Evaluation of corrosion damages and application of arc welding for repair of operating pipelines. Naft. i Gaz. Promyslovist, 6, 44-47.
17. But, V.S., Olejnik, O.I. (2007) Main trends in technology for repair of active pressurized main pipelines. The Paton Welding J., 5, 30-35.
18. Makhnenko, V.I., But, V.S., Velikoivanenko, E.A. et al. (2001) Mathematical modelling of pitting defects in active oil and gas pipelines and development of a numerical method for estimation of permissible parameters of arc welding repair of defects. Ibid., 11, 2-9.
19. But, V.S., Velikoivanenko, E.A., Pochinok, V.E. et al. (1988) Investigations of stress-strain state and prediction of serviceability of welded joints of structural elements with pipeline. In: Improvement of control and service systems of main oil transportation: Transact. Ufa: VNIISPTneft, 189-196.
20. VBN V.3.1-00013741-07:2007: Main oil pipelines. Methods of repair of defective zones. Valid 01.01.07. Kyiv: Ministry of Fuel and Energy of Ukraine.
21. GBN V.3.1-00013741-12:2011: Main gas pipelines. Repair using arc welding in service conditions. Valid 06.09.11. Kyiv: Ministry of Energy and Coal Industry of Ukraine.
22. TU U 27.2-19305558-001:2007: Reinforcing structural elements of pipelines. Valid 03.07.07.
23. But. V.S. (2003) Construction and repair of operating main gas pipelines. Manual for supervisors of welding operations on main pipelines under pressure. Kiev: PWI ITCC.

---

Suggested Citation

V.S. BUT and O.I. OLEJNIK (2014) DEVELOPMENT OF TECHNOLOGIES OF REPAIR BY ARC WELDING OF OPERATING MAIN PIPELINES IN UKRAINE. The Paton Welding J., 05, 40-47.

---