Numerical investigation on the effect of direct welding heat for on-stream repair of stainless-steel piping

• Published in: AIP conference proceedings Vol. 2453; no. 1
• Main Authors: Munir, Fudhail Abdul, Ariffin, Eddy Azrai, Soegiharto, Achmad Fauzan Hery, Sued, Mohd Kamil, Daud, Mohd Ahadlin Mohd
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Melville American Institute of Physics 25.07.2022
• Subjects: Accumulation; Austenitic stainless steels; CAD; Computer aided design; Corrosion effects; Finite element method; Inspection; Mathematical models; Numerical models; Piping; Plant shutdowns; Repair; Steel pipes; Thinning; Welding
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0095057

Corrosion has been the subject as one of the most common causes in wall thinning before leaking. Thinning pipes are possibly repaired without shutting down the plant depending on the severity of the loss wall. Methods and approaches are applied to perform online repair on piping as specified by American Petroleum Institute (API) 570 Piping Inspection Code. Example includes the repairmen process by performing on-stream welding either by using full encirclement welded split sleeve enclosure or patch, or by welding build up repair. The former is categorized as temporary repair. This study observes the repair method that includes hot work activities. Finite Element Analysis (FEA) was performed by using ANSYS Software to simulate the welding activity on respected models. The specimen material applied in the numerical model includes a 10-inch Schedule 10 ASTM A/SA312 TP304L Austenitic Stainless-Steel pipe. The final temperature of the outer wall and inner wall of each model were tabulated and analyzed. The numerical results suggest that the build up welding method is highly risky to be performed as on-stream repair as the inner surface temperature is too high, thereby igniting fire for the flammable product inside the pipe.