EN ISO 20769-1:2018 PDF

Overview

EN ISO 20769-1:2018 - “Non‑destructive testing - Radiographic inspection of corrosion and deposits in pipes by X‑ and gamma rays - Part 1: Tangential radiographic inspection” (CEN adoption of ISO 20769-1:2018) specifies fundamental film and digital radiography techniques to obtain repeatable, economical inspections of steel pipes and other cylindrical bodies (tubes, penstocks, boiler drums, pressure vessels). The standard focuses on the tangential radiographic technique used to detect and size wall loss from corrosion, pitting and erosion, using X‑ and gamma‑ray sources.

Key topics and technical requirements

• Scope and applicability: Applies to radiographic examination for service‑induced flaws (corrosion/erosion). Weld defects from welding processes are excluded except where they relate to corrosion/erosion.
• Tangential techniques: Procedures for source positions - on the pipe centre line and offset by the pipe radius - for detection and through‑wall sizing of wall loss.
• Imaging methods supported: Industrial radiographic film, computed radiography (CR) and digital detector arrays (DDA).
• Image quality and evaluation: Use of image quality indicators (IQIs), density/grey‑level requirements, minimum signal‑to‑noise, dimensional calibration and measurement methods for remaining wall thickness.
• Test setup and optimisation: Guidance on source selection, source‑to‑detector distance, beam alignment, axial coverage/overlap, and reduction of scattered/backscatter radiation (filters, collimation, shielding).
• Digital workflows: Scan/readout, calibration of DDAs, image processing, storage, viewing conditions and reporting.
• Radiation protection and personnel: Requirements for protection against ionizing radiation and personnel qualifications for radiographic work.

Practical applications and users

• Used by NDT engineers, radiographers and inspection contractors performing corrosion surveys on pipelines, process plant, power stations, boilers and pressure vessels.
• Adopted by asset owners and operators (pipeline companies, utilities, chemical plants) for routine condition assessment, remaining‑life evaluation and fitness‑for‑service inputs.
• Useful for regulators and quality managers specifying radiographic inspection methods in procurement and maintenance contracts.
• Supports decision‑making for repair, replacement or in‑service monitoring by providing repeatable, quantitative wall‑loss sizing.

Related standards

• ISO 20769‑2 - double‑wall radiography (often combined with tangential radiography).
• EN ISO 20769‑1:2018 supersedes EN 16407‑1:2014 (CEN adoption).

Keywords: radiographic inspection, tangential radiography, X‑rays, gamma rays, non‑destructive testing, corrosion inspection, computed radiography, digital detector arrays, wall loss sizing, ISO 20769‑1:2018.