Pipeline operators forum 2009 is a referenced document for the pigging inspection professionals for caliper, MFL or UT intelligent tool.
Some nomenclature are not typical terminology, yet they are particularly defined to easy the communique amongst all project team members. Pipeline Operators forum.
Definitions
Above Ground Marker: A device near the outside of a pipeline that detects and
records the passage of an ILI tool or transmits a signal that is
detected and recorded by the tool. Reference magnets can be
applied to serve identical purposes.
Anomaly: An indication, detected by non-destructive examination of an
irregularity or deviation from base pipe or sound weld
material, which may or may not be an actual flaw.
Arc strike: Localized points of surface melting caused by an electrical
arc (also referred to as hot spot).
Buckle: A partial collapse of the pipe due to excessive bending or
compression associated with soil instability, landslides,
washouts, frost heaves, earthquakes, etc
Casing: A type of feature consisting of a larger diameter pipe placed concentrically around the pipeline, usually in high stress areas such as road crossings.
Certainty: For the purpose of this specification, the probability that the
characteristics of a reported anomaly are within the stated
tolerances.
Cluster: Two or more adjacent metal loss anomalies in the wall of a
pipe or in a weld that may interact to weaken the pipeline
more than either would individually.
Confidence level A statistical expression used to describe the mathematical
certainty with which a statement is made
Corrosion: An electrochemical reaction of the pipe wall with its
environment causing a loss of metal.
Crack: A planar, two-dimensional feature with possible
displacement of the fracture surfaces.
Debris: Extraneous material in a pipeline which may interfere with
the ILI tool.
Dent: Distortion of the pipe wall resulting in a change of the
internal diameter but not necessarily resulting in localised
reduction of wall thickness.
Detection threshold: Minimum detectable feature dimension.
Feature: Indication, detected by non-destructive examination, of a
pipeline.
Geometry tool: Configuration pig designed to record conditions, such as
dents, wrinkles, ovalities, bend radius and angle, and
occasionally indications of significant internal corrosion, by
sensing the shape of the internal surface of the pipe.
Grinding: Reduction in wall thickness by removal of material by hand
filing or power disk grinding.
Gouge: Mechanically induced metal-loss, which causes localised
elongated grooves or cavities.
Heat affected zone: The area around a weld where the metallurgy of the metal is
altered by the rise in temperature caused by the welding
process, but this is distinct from the weld itself. The width of
the heat-affected zone is typically limited to a few mm only,
depending on the welding process and parameters. For the
purpose of this specification it is considered to be within 2A
of the centre line of the weld, where “A” is the geometrical
parameter related to the wall thickness.
In-Line Inspection (ILI): Inspection of a pipeline from the interior of the pipe using an
In-Line Inspection tool.
In-Line Inspection tool: Device or vehicle, also known as an intelligent or smart pig
that uses a non-destructive testing technique to inspect the
pipeline from the inside.
Intelligent pig: See “In-Line-Inspection tool”.
Joint: Single section of pipe that is welded to others to make up a pipeline.
Lamination: Imperfection or discontinuity with a layered separation, that
may extend parallel or angular to the pipe wall surface.
Metal loss anomaly/feature: An area of pipe wall with a measurable reduction in
thickness.
Mid wall feature: Any feature which does not run out to either the internal or
external surface.
Measured wall thickness: Measured wall thickness that is representative for a whole
pipe joint/component. For ultrasonic tools the value shall be
based on direct wall thickness measurements, for magnetic
tools on the inferred magnetic flux signals.
Measurement threshold: The minimum dimension(s) of a feature to make sizing
possible.
Nominal wall thickness: The wall thickness required by the specification for the
manufacture of the pipe.
Pig: Device that is driven through a pipeline for performing
various internal activities (depending on the pig type) such as
separating fluids, cleaning or inspecting the pipeline.
Pigging: Running of a pig or ILI tool in a pipeline.
Pig trap: An ancillary item of pipeline equipment, with associated
pipework and valves, for introducing a pig into a pipeline or
removing a pig from a pipeline.
Pipeline: A system of pipes and other components used for the
transportation of products between (but excluding) plants. A
pipeline extends from pig trap to pig trap (including the pig
traps), or, if no pig trap is fitted, to the first isolation valve
within the plant boundaries or a more inward valve if so
nominated.
Pipe mill anomaly: An anomaly that arises during manufacture of the pipe, as for
instance a lap, sliver, lamination, non-metallic inclusion, roll
mark and seam weld anomaly.
Pipeline component: A feature such as a valve, tee, bend, weld, casing, marker, off
take, wall thickness change, etc. that is a fitted part of a
pipeline
Probability of Detection: The probability of a feature being detected by the intelligent
pig.
Probability of Identification: The probability that an anomaly or a feature, once detected,
will be correctly identified
Reference magnet: See Above Ground Marker
Reference wall thickness: The actual undiminished wall thickness surrounding a
feature, used as reference for the determination of the feature
depth.
Reporting threshold: Parameter, which defines whether or not a feature will be reported.
Sizing accuracy: Sizing accuracy is given by the interval with which a fixed
percentage of features will be sized. This fixed percentage is
stated as the certainty level.
Spalling: Abrasion of the pipe surface resulting in shallow surface laps
and possibly hardening of the material below.
Weld: The area where joining has been done by welding and where
the material has undergone a melting and solidification
process. This area is distinct from the heat-affected zone, but
surrounded by it.
Weld anomaly: Anomaly in the weld or the heat affected zone.
Weld affected area: Area on both sides of a weld where ILI measurements are effected by the geometry of the weld (e.g. due to sensor dynamics).
Abbreviations Nomenclature
A - Geometric parameter related to the wall thickness AGM - Above Ground Marker D - Metal loss anomaly depth EC - Eddy Current EMAT Electro - Magnetic Acoustic Transducer ERF - Estimated repair factor GPS - Global Positioning System HFEC - High Frequency Eddy Current ILI - In Line Inspection L - Anomaly/feature dimension (Length) in the axial direction and length of crack in any direction MAOP - Maximum Allowable Operating Pressure MOP - Maximum Operating Pressure MFL - Magnetic Flux Leakage NDE/NDT - Non-Destructive Examination, Non-Destructive Testing POD - Probability Of Detection POI - Probability Of Identification Psafe - Safe operation pressure as per calculated defect assessment method T - Wall thickness UT - Ultrasonic Technique W - Anomaly/feature dimension (Width) in the circumferential direction and opening dimension for cracks (if applicable).