Introduction Composite repairs are gaining popularity and acceptance worldwide among asset owners and operators. Composite repair methods and procedure are guided international engineering standards and provide an engineered, proven and durable solution to non-metallic pipe repair works. Components of composite repair materials generally comprise of filler rebuilding material, resin component and reinforcement layered sheet. Filler…
Introduction In corrosion prevention by anti-corrosion coatings, three main principles are employed in various combinations: Create a barrier that keeps out charged ions and retards the penetration of water and oxygen. Ensure contact between the steel and a less noble metal (e.g. zinc in the coating) provides cathodic protection of the steel utilizing the galvanic…
Introduction One of the main considerations that need to be taken into account when using a pipe repair clamps is the ability of the repair system to accommodate the pressure imposed axial loadings/stresses. The other main consideration is the pipe remaining wall thickness – if the mechanical strength of the pipe is sufficient to withstand…
Introduction This chapter covers the major types of coatings that are currently available for use and includes general information on the composition of coatings. It is intended to give basic information on coatings and is not a comprehensive guide to anti-corrosion coatings selection. The coating manufacturer is to be consulted if information on a specific…
Introduction Most pipe repair components have a design basis in accordance with internationally recognised codes or standards. However in most cases these codes or standards may not concern piping or pipelines, but concern pressure vessel type codes, such as ASME Section VIII: Pressure Vessel Code, or API 6H: Specification on End Closures, Connectors and Swivels. Pressure vessel…
Introduction Good surface preparation may be considered to be the most important part of the entire coating process in that the greatest percentage of coating failures can be traced directly to poor surface preparation. All paint or anti-corrosion coating systems will fail prematurely unless the surface has been properly prepared to receive the coating. If…
Common Causes of Flange Leakage A previous article highlighted the primary causes of flange leakage. This article provides more information about these. Uneven Bolt Stress. An incorrect boltup procedure or cramped working conditions near the flange can leave some bolts loose while others are overtightened and crush the gasket. This can cause in-service leaks, especially…
Introduction Experience has shown that edges and welds are generally the first areas to show corrosion and coating breakdown, particularly in ballast and cargo tanks. This is due to a number of inter-related processes including surface preparation, coating application, deflection, and shear and buckling stresses on the edges and welds and so on. The quality…