The purpose of this technical committee report is to analyze available and emerging technologies in the field of in-line inspection tools and review their status with respect to characteristics, performance, range of application, and limitations. It is intended as a practical reference for both new and experienced users of ILI technology. This is a support document for the API(1) 11631 standard where it is referenced.

The document pertains to free swimming tools, as used predominantly in transmission pipelines, but the technologies are sometimes applicable in tethered tools and in other types of pipelines, such as gathering and distribution lines.

This report is aimed at assisting in providing an understanding of the practical aspects of using the tools, highlighting the implications, and helping assess the benefits.