The aim of this second edition of MACAW's Encyclopedia of Pipeline Defects (the first edition of which was published as MACAW's Pipeline Defects) is to illustrate the range of defects that may be encountered in high-pressure steel pipelines and their pipeline coatings. It gives advice on the probable cause and significance of the defects and comments on appropriate remedial actions. This book is not intended as a "Do-It-Yourself Manual" for the diagnosis and analysis of defects, and use of this manual will not make the user an 'instant expert'. Many of the defects require analysis and diagnosis by a qualified expert using specialist analytical techniques.