Irregularity of the circular section of a component, quantified by the difference in the largest and smallest cross-sectional axes.
Source: ISO 14692-1:2017, Petroleum and natural gas industries — Glass-reinforced plastics (GRP) piping — Part 1: Vocabulary, symbols, applications and materials, Second Edition, August 2017. Global Standards
Ratio of the difference between the maximum and minimum diameter to the sum of the maximum and minimum diameter of the pipe.
Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards