Repair of Through-Wall Corrosion Damage in Pipes Using Bonded Metallic Patches - Influence of the Patch Thickness on the Failure Pressure

Abstract

ABSTRACT This paper is concerned with the repair of through-wall corrosion damage in metallic pipes using bonded metallic patches. The focus is on the analysis of the influence of the thickness of the patch on the effectiveness of the repair. The goal is to assure that the pipe won’t leak once the repair is completed. Usually, in practical applications, a composite sleeve is used combined with a metallic patch. The study shows that only a bonded metallic patch can be sufficient to avoid leaking (no composite sleeve is necessary), but the effectiveness of the repair is strongly dependent on its thickness. Experimental results show that the failure pressure using patches with the same area but with different thicknesses can be very different. Burst tests were performed on API 5 L grB steel hydrostatic specimens with a 25 mm hole repaired with 100 mm × 100 mm patches. Depending on the thickness, the failure pressure can vary from 70 to 270 bar. A model based on the Linear Elastic Fracture Mechanics is proposed to obtain an estimate of the failure pressure using only one algebraic equation. The experimental results are in good agreement with model predictions.