The annotation behind the definitions below refer to the standard used. knowing the accuracy and reliability of ili measurements is important for determining optimum integrity rehabilitation project scope, re- inspection interval and the risk associated with the pipeline section examined. the recent ( september ) introduction of api 1163 ( title) highlights the importance of these metrics. api std 1163 aug in- line inspection systems qualification standard this standard covers the use of in- line inspection systems for onshore and offshore gas and hazardous liquid pipelines. the main purpose of this project is pdf to provide technical guidance for the practical implementation of the measurement performance validation methodologies outlined in the api rpedi- tion ( api, which include three levels of validation: level 1 : the vendor specification is used to define measurement performance with little or no field validation. this standard covers the qualification, selection, reporting, verification, validation, and use of in- line inspection ( ili) systems for onshore and offshore steel gas and hazardous liquid pipelines. d11632 pdf this standa rd covers the use of in- line inspection ( ili i) systems for r onshore and offshore gas a and hazardous s liquid pipeli nes. references this document references:. api stan ndard rd 11 63 in- line e inspec ction sy ystems s qualif ication second ed dition api 1163 pdf | april l | 79 pag ges | $ 131. this standard serves as an umbrella document to be used with and complement companion standards ( see figure 2 ). this includes, but is not limited to, tethered or free flowing systems for. during the update of this specification, standards such as e. api std 1163, 3rd edition, september - in- line inspection systems qualification. however, if referenced standards are in conflict with this ( pof) specification, this specification prevails. five years later, the first edition of api standard 1163, in- line inspection systems qualification, was published in august [ 3]. this includes, but is not limited to, tethered, self. api 1163 [ 1], pdam [ 2] and cepa [ 3] have been reviewed and some definitions have been aligned.