Latest revision of the DNV Offshore Standard for Submarine Pipeline Systems, DNV-OS-F101

The third revision of the DNV Offshore Standard for Submarine Pipeline Systems, DNV-OS-F101, is now available providing significant improvements based on solid feedback from the industry. Close to 1,000 comments were received during the consultation process.

The trigger for the revision has been to align the standard with the new ISO 3183 on linepipe and the new ISO coating standards. In addition, DNV has gained experience and received considerable feedback from the industry and wished to incorporate this into the standard.

Three main changes
Although there are significant improvements in the new revision, most of these involve restructuring and clarifications. The three main changes are as follows:

Firstly, the concept development and design premises section has been reorganised into a more chronological order. The part on pressure control systems has been slightly restructured and generalised – restructured in the sense that pressures are defined and generalised in that the control system is no longer limited to pressure alone but has been extended to all critical operational parameters, such as temperature, content and minimum temperature, content and minimum pressure, and the term operating envelope has been introduced for this purpose.

The second main change is in the installation section, which is now termed “Construction – Offshore” as it includes pre-installation as well as post-installation (e.g. precommissioning) activities. This is based on several workshops with Statoil and the section is now more balanced with respect to the extent of the activities and is organised in chronological order. In addition to the reorganisation, de facto changes in this section relate to marine operations and equipment qualification.

The third main change relates to non-destructive testing (NDT) and automated ultrasonic testing (AUT). As this has been a less mature area in terms of technology compared to other parts, the experience gained over the last five years and from the new DNVRP- F118 on the qualification of AUT systems was expected to necessitate some updates.

Published in Valve User Magazine Issue 23

Summer 2020 // Issue 53
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