Magnetic Flux Leakage Testing (MFL) Services in Spain 2026 — Atlantis NDT

How Magnetic Flux Leakage (MFL) works

MFL saturates a ferromagnetic wall with a magnetic field; where metal is missing, flux leaks out of the wall and is detected by sensors passing over the surface. It scans large ferrous areas quickly, which is why it dominates storage tank floor screening and in-line pipeline inspection.

What it detects

• Tank floor corrosion and pitting from both the product side and the soil side, at scanning speeds no point-by-point method can match
• Pipeline wall loss during in-line inspection runs, with axial and circumferential field variants suited to different defect orientations
• Under-deposit and soil-side corrosion that visual examination cannot see
• General wall loss across large ferrous plate areas for screening before detailed UT

What it will not do

MFL is a screening method whose sizing accuracy depends on wall thickness, coating thickness, defect geometry and scanning speed. Indications are confirmed and sized by ultrasonic prove-up. It also degrades on thick walls, on heavily coated surfaces, and on non-ferrous materials where it does not work at all.

When Magnetic Flux Leakage (MFL) is the right choice

Choose MFL to screen large ferrous areas fast — tank floors before an internal inspection scope is set, or pipeline runs where in-line inspection is available — then size with UT what MFL finds.

Codes and acceptance criteria

Examinations are performed to written procedures qualified against API 653 for aboveground storage tank inspection including floor evaluation, API 570 and ASME B31.8S for pipeline integrity assessment, ASTM E570 for flux leakage examination of ferromagnetic tubing, and POF specifications for in-line inspection performance. Acceptance criteria come from the construction or in-service code governing the item — ASME Section VIII for pressure vessels, ASME B31.3 for process piping, API 510, API 570 and API 653 in service, AWS D1.1 for structural steel — and the applicable edition is recorded against the examination so the disposition can be reconstructed later.

Spain context

Spain hosts a diverse refining and renewables industrial base, with Repsol's Cartagena, Tarragona, Petronor (Bilbao), Coruña, and Puertollano refineries (collectively 900,000 bpd), Cepsa's San Roque and Huelva refineries, and BP's Castellón refinery. The Iberdrola Cofrentes nuclear plant, the Almaraz and Trillo PWR units, and the offshore wind pipeline in Galicia and the Canary Islands drive parallel inspection demand. The CNS (Consejo de Seguridad Nuclear) and the Ministerio para la Transición Ecológica oversee a tightening compliance environment under PED 2014/68/EU. Repsol's renewable-diesel and SAF conversion programme at Cartagena creates immediate baseline-capture opportunities for digital twin contractors.

How the examination is controlled

Every examination carries its own evidence chain: the technician's certification for the method and level under ASNT SNT-TC-1A or ISO 9712, current on the day of inspection; the calibration status of the instrument, probes, wedges and reference blocks used, traceable under ISO 17025; and the revision of the procedure and technique sheet in force at the time. An ASNT NDT Level III reviews and signs the final disposition. That bundle is exactly what a client or accreditation audit asks for, and it is recorded as the work happens rather than assembled afterwards.

What you receive

• A report in your required format, with indications located against the component and, where relevant, against a persistent corrosion monitoring location so trends stay continuous between campaigns
• Raw data files in the instrument-native format plus an open export, so the dataset outlives any single supplier relationship
• The procedure revision, technician certification state and instrument calibration status applicable at the time of examination
• Where a finding affects continued service, a clear statement of the code clause that governs the acceptance decision

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