SIST EN ISO 20601:2019 PDF

Overview - EN ISO 20601:2018 (Ultrasonic phased array for thin-walled steel welds)

EN ISO 20601:2018 specifies the application of automated phased array ultrasonic testing (PAUT) for semi‑ or fully‑automated inspection of fusion-welded joints in thin‑walled steel components. The standard targets wall thicknesses between 3.2 mm and 8.0 mm (typical boiler/tube ranges) and applies to full‑penetration welds of simple geometry in plates, tubes, pipes and vessels where both weld and parent material are low‑alloy and/or fine‑grained steel. It supports pre‑service testing of new and repair welds and permits phased array UT to be used alone or combined with other NDT methods.

Key topics and technical requirements

• Testing scope: Semi‑automated (manually moved probes with positional encoding) and fully‑automated (mechanized propulsion) PAUT for thin walls. Level “D” permits exceeding the nominal thickness range for special cases; level “C” covers standard situations.
• Material ultrasonic parameters: Default calibration velocities are longitudinal 5920 ± 50 m/s and transverse 3255 ± 30 m/s; users must account for different material velocities.
• Procedure essentials: Information required before testing, written test procedures, personnel qualifications, equipment and probe specifications, scanning mechanisms, couplant, temperature and surface preparation.
• Calibration and verification: Reference blocks, test block requirements (especially for level D), instrument/display checks, and verification of test setup.
• Data handling: Data storage, phased array data interpretation, assessment of indication quality, location, sizing and characterization.
• Assessment methods: Indications assessed for acceptance based on height & length, amplitude (equivalent reflector size) & length, or go/no‑go decisions. Note: EN ISO 20601:2018 does not define numerical acceptance levels for discontinuities.

Practical applications

• Inspection of boiler tubes, heat‑exchanger tubing, thin‑walled pipes and vessels where welding quality is critical.
• Manufacturing quality assurance, pre‑service acceptance testing, and verification after weld repairs.
• Automated inline inspection where repeatability and positional accuracy of phased array data are required.

Who should use this standard

• NDT engineers and technicians implementing PAUT for weld inspection.
• Inspection companies and fabrication quality managers in boilers, power plants, petrochemical and pressure‑equipment industries.
• Standards writers, regulatory authorities and procurement/specification writers who require harmonized PAUT procedures for thin‑walled steel components.

Related standards

• Applicable alongside other international and national ultrasonic testing and weld inspection standards and ISO technical committee guidance for welding and allied processes (ISO/TC 44). Use EN ISO 20601:2018 in concert with organization‑specific acceptance criteria and industry codes.