Piping systems that have not been isolated and decontaminated, i.e. still connected to in-service process equipment
- NOTE: Piping systems that are on-stream can be full of product during normal processing or empty or may still have residual process fluids in them and not be currently part of the process system (e.g. temporarily valved-out of service).
Source: API 570, Piping Inspection Code: In-service Inspection, Rating, Repair, and Alteration of Piping Systems, Fourth Edition, February 2016, with Addendum May 2017. Global Standards