Non-Destructive Examination(NDE/NDT)

An NDE method that uses high-frequency sound waves to detect internal flaws and measure wall thickness in materials. A transducer sends ultrasonic pulses into the material; reflections from internal surfaces, flaws, or the back wall are analyzed to determine thickness, flaw size, and flaw location. UT techniques include conventional (A-scan), phased array (PA-UT), time-of-flight diffraction (TOFD), guided wave (GWUT), and automated/semi-automated scanning (AUBT).

An NDE method for detecting surface and near-surface discontinuities in ferromagnetic materials. The test surface is magnetized (using a yoke, prods, or coil) and ferromagnetic particles (dry powder or wet suspension) are applied. Particles accumulate at areas of flux leakage caused by discontinuities, forming visible indications. MPI is highly sensitive to surface-breaking cracks, particularly fatigue cracks, stress corrosion cracks, and weld defects.

An NDE method that uses penetrating radiation (X-rays or gamma rays) to produce an image of the internal structure of a component. The radiation passes through the material and is captured on film or a digital detector. Variations in material thickness, density, or internal flaws appear as contrast differences on the image. RT is effective for detecting volumetric flaws (porosity, inclusions, voids) and some planar flaws (cracks oriented favorably to the beam).

The most fundamental NDE method, involving direct or remote visual examination of equipment surfaces for signs of degradation, damage, leakage, misalignment, or other anomalies. Visual inspection detects surface conditions including corrosion, coating breakdown, distortion, discoloration, leakage staining, insulation damage, and mechanical damage. It may be performed directly, with magnification aids, or remotely using cameras, borescopes, or drones.

A qualitative rating of the probability that an inspection activity will correctly identify and characterize the damage present in the inspected equipment. Inspection effectiveness is categorized from A (Highly Effective — high probability of detecting the damage) through E (Ineffective — virtually no chance of detection). The rating depends on the inspection technique used, the skill of the inspector, the coverage area, and the damage mechanism being sought.

A specific process or phenomenon that causes degradation of material properties, leading to eventual failure of equipment. Damage mechanisms include corrosion (uniform, localized, galvanic), erosion, fatigue, creep, hydrogen damage, stress corrosion cracking, embrittlement, and other metallurgical or environmental attack modes. API 571 catalogues over 60 damage mechanisms relevant to refining and petrochemical equipment.