Composites sleeves are an extremely popular alternative to cut and replace, welded sleeves and clamps for the repair of up to 80% external metal loss defects. Composites have an excellent proven track record with over 100 composite sleeve repairs being installed daily in over 80 countries. Composites have also been developed, tested and peer reviewed as being suitable for the reinforcement of mechanical damage on liquid and gas pipelines. This paper looks at the European and International research undertaken regarding the reinforcement of mechanical damage including dents, gouges and vandalism with reference to both ASME B31.4 (2016) and ASME B31.8s (2014), and provides clarification on where a composite sleeve repair would be suitable, and where it would not. The paper then gives examples of where European operators of both liquid and gas pipelines have installed composite sleeve repairs over mechanical damage and provides a justification as to why these repairs were suitable and highlights the cost and time benefits of selecting a composite sleeve over other code accepted methods to complete an pipeline-in-service repair.