PL Fit for Service Overview

The fitness for service assessment approach in IMS PLSS is based on pipeline corrosion defects assessment codes such as DNV RPF-101 and ASME B31G.

The fitness for service assessment, in general, is based on two approaches:

• ILI/IP data – standard assessment in the FFS module.

• Non-piggable assessment – an assessment that caters to the case where inspection data is not from ILI/IP.

We advice that the technical authority for the Pipeline and subsea asset class should ensure that the fitness for service assessment is:

• Conducted for all types of defects and loading conditions above workmanship standards.

• Duly record in an appropriate system, or in the element section of IMS PLSS where the assessment is not calculated by IMS PLSS (for age-related degradation with a volumetric morphology and a plastic collapse limit state predominantly under internal pressure using level 1 assessment methods, i.e. a burst of corrosion defects).

Note: For Shell this is inline with AMS RP 4-04.8.

The relationship between the generalized workflow and IMS PLSS for the fitness for service assessment is defined in Figure below.

In addition to this FFS online manual also refer to:

Document	Comment
PL Non-Piggable Pipelines
PL ILI Comparison
DNV RP-F101 - Corrodate Pipelines	See attached pdf
DNV RP-F101 Jan 2015	See attached pdf
DNV-OSF-101 - SUBMARINE PIPELINE SYSTEMS
w-PIMS FFS Theory Doc	See attached pdf
Best Practice Guide: Integrity Assessment of Non-Piggable Pipelines	Only applicable for Shell
Best Practice Guide: Pipeline Defect Assessment Manual	Only applicable for Shell