ISO 23876:2022

Overview

ISO 23876:2022 specifies the use of acoustic emission examination (AT) for periodic inspection and testing of composite transportable gas cylinders and tubes (water capacity up to 3 000 L). It applies to hoop-wrapped (Type 2), fully wrapped (Types 3 and 4) and linerless (Type 5) composite cylinders with aluminium-alloy, steel or non‑metallic liners, intended for compressed and liquefied gases. The standard is focused on verification of the composite overwrap material only; internal visual inspection of liners is excluded (see ISO 11623).

Key topics and technical requirements

• Scope and applicability: AT for composite cylinders/tubes (Types 2–5), up to 3 000 L; addresses only composite material performance.
• Acoustic emission fundamentals: AE sources in composites include fibre breakage, matrix cracking and delamination; AEs are detected as transient elastic waves using piezoelectric sensors.
• Equipment and calibration: Requirements for AE instrumentation, sensors, preamplifiers, filters and settings; calibration and verification procedures referenced to recognised methods (e.g., ASTM E1106, EN characterisation standards).
• Sensor layout and location: Linear location requires at least two sensors (one near each end); three or more sensors needed for planar/geodesic source location.
• Test validation and rejection criteria: Selection and verification of AE parameters and rejection criteria via tests on undamaged, acceptable-damage and unacceptable-damage cylinders (examples in Annex A/B). If criteria cannot discriminate damage, AT must not be used for that design.
• Personnel qualification: Operators must be certified per ISO 9712 (minimum Level I operator supervised by Level II/III); organisations should retain a Level III to oversee AT programmes.
• Documentation: Test inputs must record cylinder construction, fibre/resin types, manufacturer, capacity, diameter and working pressure; reporting requirements and criteria for rendering cylinders unserviceable are specified.

Practical applications and users

ISO 23876 supports safe, evidence‑based periodic inspection of composite gas cylinders through non‑destructive testing (NDT). Typical users:

• NDT service providers and AE technicians
• Cylinder manufacturers and design engineers
• Cylinder testing and repair facilities
• Gas producers, distributors and fleet maintenance teams
• Certification bodies and regulators overseeing transport and storage of pressurised gases

Benefits include targeted verification of composite integrity, early detection of delamination or fibre damage after mechanical impact, and standardised AE testing practices for inspection programs.

Related standards

• ISO 11623 - Periodic inspection of composite cylinders (hydraulic/visual)
• ISO 16148 / ISO/TS 19016 - AE methods for metallic and composite cylinders
• ISO 9712 - Qualification and certification of NDT personnel
• ISO 10286, ISO/IEC 17025 and referenced EN/ASTM AE characterisation standards

Keywords: ISO 23876, acoustic emission, AE testing, composite gas cylinders, periodic inspection, non-destructive testing, NDE, Type 2 Type 3 Type 4 Type 5.