The Paton Welding Journal, 2010, №01



2010 №01 (01)

2010 №01 (03)

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TPWJ, 2010, #1, 7-10 pages
 
RISK OF FRACTURE OF PRESSURISED MAIN PIPELINE WITH DEFECTS OF THE TYPE OF WALL THINNING DURING REPAIR


Journal                    The Paton Welding Journal
Publisher                 International Association «Welding»
ISSN                       0957-798X (print)
Issue                       № 1, 2010 (January)
Pages                      7-10
 
 
Authors
V.I. MAKHNENKO, V.S. BUT, S.S. KOZLITINA and O.I. OLEJNIK
E.O. Paton Electric Welding Institute, NASU, Kiev, Ukraine
 
 
Abstract
It is shown that welding repair of defects of the type of pipeline wall thinning by compensating the metal lost in the thinning zone by the deposited metal using low-current (~90 A) manual arc weld deposition is a sufficiently efficient technology. Wide application of this technology for repair of pressurised main pipelines is limited by the safety problem. Also, it is shown that the minimum admissible wall thickness in the defect zone under operating pressures depends upon the size of a defect along the generating line and, to a much lesser degree, upon its size on the circumference, as well as upon the thermal parameters of welding and accepted sequence of welding-up (deposition) of the defect.
 
 
Keywords: main pipelines, pressure, thinning defects, minimal thickness, welding repair, welding sequence
 
 
Received:                ??.??.??
Published:               28.01.10
 
 
References
1. 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. The Paton Welding J., 11, 2-9.
2. Bruce, W.A., Mishier, H.D., Kiefner, J.F. (1993) Repair of pipelines by direct deposition of weld metal: A.G.A. Pipeline Research Committee Project PR-186-9110. Edison Welding Institute.
3. Bruce, W.A., Swatzel, J.F., Dorling, D.V. (2000) Repair of pipeline defects using weld deposition. In: Proc. of 3rd Int. Pipeline Technology Conf. (Brugge, Belgium, May 21-24, 2000).
4. Fitness-for-service: American Petroleum Institute Recommended Practice 579.

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