Each operator that uses direct assessment as defined in section 255.903 of this Part on an onshore transmission line made primarily of steel or iron to evaluate the effects of a threat in the first column must carry out the direct assessment according to the standard listed in the second column. These standards do not apply to methods associated with direct assessment, such as close interval surveys, voltage gradient surveys, or examination of exposed pipelines, when used separately from the direct assessment process.
|
Threat |
Standard |
|
External corrosion |
|
|
Internal corrosion in pipelines that transport dry gas |
|
|
Stress corrosion cracking |
(a) For lines not subject to the Pipeline Integrity Management requirements of this Part, the terms covered segment and covered pipeline segment in sections 255.925, 255.927, and 255.929 of this Part refer to the pipeline segment on which direct assessment is performed.
(b) In section 255.925(b) of this Part, the provision regarding detection of coating damage applies only to pipelines subject to the pipeline integrity management requirements of this Part.