scope:

This recommended practice gives guidance on design for two global buckling scenarios for high temperature and high pressure pipelines:

1) Unburied pipelines on even and uneven seabed where global buckling occurs either fully in the horizontal plane, or first in the vertical plane as feed-in and uplift and subsequently in the horizontal plane.

2) Buried pipelines where global buckling occurs in the vertical plane, so called upheaval buckling. Only criteria for avoiding upheaval buckling are given in this recommended practice.

Detailed design procedures and criteria are given for global buckling of unburied pipelines on even and uneven seabed and to avoid upheaval buckling of buried pipelines. The methodology and criteria are valid for offshore rigid steel pipelines.

The recommended practice also contains examples of mitigation measures, some examples on probabilistic buckle formation calculations and guidance on effect of sour service.