The application of requirements contained in many industry codes and standards requires some interpretation by the user and by the regulator who is called upon to enforce their use. There are often differences in the way requirements are interpreted because of ambiguous specification language, unclear rationale behind the requirements, or novel or non-traditional applications. Some industry codes and standards contain guidance in the form of commentary sections or companion documents to assist in matters of interpretation and application. Until recently, this was not the case for API Standard 1104 – Welding of Pipelines and Related Facilities,(1) where requests for interpretation have been frequent because of unclear requirements or an absence of information pertaining to rationale.
This paper describes a project sponsored by Pipeline Research Council International (PRCI) and carried out by DNV GL that resulted in the development of a guidance document for API 1104.(2)