A safety factor of 1.39 was used for the assessment of anomalies based on an MAOP of 46 bar. For example, if the failure pressure of an anomaly is calculated to be 139 bar, then the safe working pressure will be 100 bar.

1.39 is a safety factor used in ASME B31.G, and retained for primary use in the Modified ASME B31.G[1]. It is based on a pipeline operating at 72% SMYS being able to withstand a hydrotest of 100% SMYS.

MAOP of 52.8 bar

A safety factor of 1.25 was used for the assessment of anomalies based on an MAOP of 52.8 bar. This safety factor has been derived based on the ratio of the maximum operating stress on the thinnest pipe at MAOP to the yield strength. This has been increased to 1.25 which is the minimum safety factor allowed by the Modified ASME B31.G.