Glossary

ABI® is a nondestructive mechanical testing technique for determining tensile and fracture toughness properties.

Testing method that generates small spherical indentations on the pipe surface that are analyzed to determine the pipe’s mechanical properties.

Pretesting and adjusting of equipment prior to the actual test to ensure the equipment performs within acceptable levels.

A calculated value based on the chemical composition of pipe steel which is a rating of its weldability.

Mechanical testing method that measures the amount of energy absorbed by a pipe sample during fracture to determine material toughness.

Determines the chemical elements present in a sample of pipe and their composition percentage.

A movable cross head (crosshead) is controlled to move up or down.

Any discontinuity that does not meet the specified acceptance criteria.

Involves removal of pipe specimens for testing of mechanical/chemical properties, often in a laboratory. Tests are often carried out to the specimen’s failure (i.e., Charpy V-notch tests).

Refers to the direction of product flow in a pipeline. In pipelines where flow is bidirectional or unknown, “downstream” will refer to the direction of increasing engineering stationing.

The ability of a material to deform plastically before fracturing. Measured by elongation or reduction in area in a tensile test, by height or cupping in a cupping test, or by the radius or angle of bend in a bend test.

An industrial power tool that uses an abrasive wheel for cutting or removing the material. The grinding is finishing operation to show the high surface quality, accuracy of the shape and dimension.

NDT indications caused by conditions such as part geometry (blind holes, keyways), magnetic writing, localized hardening and scratches. They are considered non-relevant.

Progressive and localized structural damage that occurs when a material is subjected to cyclic loading.

A quantitative way of expressing a material's resistance to brittle fracture when a crack is present. If a material has high fracture toughness, it is more prone to ductile fracture. Brittle fracture is characteristic of materials with less fracture toughness

Circumferential weld joining joints of steel pipe or pipe components.

A rating of the size of abrasive materials on the sandpaper. The higher grit number is equivalent to a finer abrasive, which creates smoother surface finishes. Lower grit numbers represent coarser abrasives that scrape off materials much quicker.

The resistance of a material to deformation, particularly permanent deformation, indentation or scratching.

Testing method that generates small, shallow grooves on the pipe surface which are analyzed to determine its mechanical properties.

Mechanical component used to apply a load to the surface of the material.

The response or evidence from a nondestructive examination.

The linear variable differential transformer is a type of electrical transformer used for measuring linear displacement.

Maximum Allowable Operating Pressure (MAOP)  maximum pressure at which a pipeline or segment of a pipeline may be operated.

Mechanical properties of a metal or material relate to its behavior when subjected to a force or load during testing. In mechanical testing, the behavior of the metal is either elastic or inelastic. Elastic behavior occurs with no permanent damage to the test sample. In contrast, inelastic behavior is observed when a material is permanently deformed by the applied force, and therefore, does not return to its original shape.

Testing method that has no effect on mechanical or chemical properties and may be safely completed while a component/specimen is in service.

NDT indication that is caused by a condition or type of discontinuity that is not rejectable.

PHMSA-defined process requiring that any individual performing an identified task on the pipeline has been evaluated to ensure they have the necessary knowledge, skills, and abilities to complete the task safely and effectively.

A mechanical, chemical, and/or electrolytic process used to prepare a smooth reflective surface free from artifacts or damage introduced during sectioning or grinding and suitable for microscopic examination.

Determination of a pipe’s chemical properties

A thin layer of solid material on a surface that provides improved protective, decorative, or functional properties. More specifically, they are a liquid, liquefiable, or mastic composition that, after application to a surface, is converted into a solid protective, decorative, or functional adherent film.

NDT indication that is caused by a condition or type of discontinuity that requires evaluation.

The amount of load or stress that a material can handle until it stretches and breaks. As its name implies, tensile strength is the material’s resistance to tension caused by mechanical loads applied to it.

The maximum stress that a pipe can withstand while being stretched or pulled before breaking.

Non-destructive test method that uses sound waves to determine the wall thickness of pipe or to characterize defects, if present.

Maximum stress that can be applied to a pipe before it begins to change shape permanently.