Overview
ISO 22500:2026 specifies requirements and procedures for magnetic flux leakage (MFL) testing to detect corrosion and mechanical defects in in-service equipment made from ferromagnetic materials, such as steel plates and steel pipes. As a critical standard for non-destructive testing (NDT), ISO 22500:2026 ensures safe and efficient evaluation of metal loss caused by corrosion or damage, aiding industries in reliable asset integrity management.
This document is particularly valuable for operators of pressure vessels, seamless steel pipes, and storage tanks, focusing on base metals with specific dimensional criteria. The standard also permits MFL testing through coatings up to 6 mm thick, making it suitable for real-world applications where protective coatings are present.
Key Topics
- Magnetic Flux Leakage Testing Method: Outlines principles, system components (magnetization device, sensors, scanning device), and performance criteria.
- Detection Capability: Supports identification of volumetric defects (such as corrosion and mechanical damage) on both accessible and opposite surfaces.
- Applicable Equipment: External testing of ferromagnetic seamless steel pipes and pressure vessel shells (outer diameter ≥ 38 mm, wall thickness ≤ 20 mm), and storage tank bottom plates (wall thickness ≤ 20 mm).
- Personnel Qualification: Test personnel must be certified and competent, following ISO 9712 requirements.
- Site and Testing Preparation: Describes preliminary information collection, site investigation, and removal of interfering materials like rust or debris.
- Testing Procedures: Specifies systematic approach to scanning, sensitivity checks, and adjustments for optimal accuracy.
- Data Evaluation: Provides guidance for interpreting test results, setting defect thresholds, and marking findings.
- Recommended Actions: Suggests follow-up inspections (visual, hammer, ultrasonic) based on MFL findings.
- Documentation: Details required structure and content of test instructions, test records, and test reports for traceability and repeatability.
Applications
Magnetic flux leakage testing according to ISO 22500:2026 is highly relevant for a variety of sectors relying on the integrity of steel infrastructure, including:
- Oil & Gas Pipelines: Routine inspection of pipelines for corrosion and mechanical damage, minimizing the risk of leaks and failures.
- Pressure Vessel Maintenance: Ensures the safe operation of vessels under pressure by detecting subsurface and surface defects before serious issues occur.
- Storage Tank Bottom Plates: Supports the evaluation of tank bottoms, critical for environmental protection and regulatory compliance.
- Chemical Processing Plants: Ongoing monitoring of process equipment where corrosion or wear poses operational risks.
- Power Generation: Inspection and maintenance planning for boilers and steam pipelines in power plants.
The method can be applied to both manually and automatically operated scanning systems, with adjustments for coated and uncoated surfaces. By implementing this standard, organizations can improve maintenance forecasting, extend asset service life, and comply with industry safety requirements.
Related Standards
ISO 22500:2026 refers to and aligns with several foundational and complementary standards in the field of non-destructive testing:
- ISO 9712: Non-destructive testing - Qualification and certification of NDT personnel
- ISO 12707: Non-destructive testing - Magnetic particle testing - Vocabulary
- ISO 12718: Non-destructive testing - Eddy current testing - Vocabulary
- ISO 16809: Non-destructive testing - Ultrasonic thickness determination
Other closely associated standards and guidelines:
- ASME BPVC Section V, Article 16 (Magnetic Flux Leakage Examination)
- SAC standards for atmospheric storage tanks and pressure equipment
By adhering to ISO 22500:2026, engineers and inspectors ensure high standards of reliability in corrosion detection and contribute to the overall safety and longevity of critical steel infrastructure.