Overview - EN ISO 16148:2016 (Gas cylinders AT/UT)
EN ISO 16148:2016 specifies procedures for acoustic emission (AT) examination and follow-up ultrasonic (UT) testing used during the periodic inspection and testing of refillable seamless steel gas cylinders and tubes (water capacity up to 3 000 L) for compressed and liquefied gases. The standard defines how AE indications are detected and located during AT and how a secondary UT examination is used to evaluate the significance of those indications. Composite cylinders are excluded.
CAUTION - Some tests specified may create hazardous situations and require appropriate safety controls.
Key topics and requirements
- Scope and applicability: Refillable seamless steel cylinders and tubes (≤ 3 000 L), periodic inspection and testing; excludes composite cylinders.
- AT methods: Two AT methods (Method A and Method B) are described for detecting acoustic emission (AE) sources during pressurization.
- Follow-up UT: Ultrasonic examination (typically shear-wave/angle-beam UT) is used immediately after AT to assess AE indications for possible flaws.
- Pressurization: Tests require pressurization above normal filling pressure; the medium may be gas or liquid.
- Personnel qualification: NDT personnel must be qualified per relevant standards (e.g., ISO 9712).
- Equipment and calibration: AT equipment calibration and verification requirements are specified (referenced equipment characterization standards such as EN 13477).
- Safety and procedures: Special considerations to ensure valid tests and safe operation are provided, including real‑time evaluation criteria and reporting requirements.
- Annexes: Normative annexes cover UT follow-up procedures, AT equipment specs, example instrument settings, source location alternatives and distance amplitude correction (DAC) guidance.
Practical applications and users
Who uses EN ISO 16148:2016:
- Inspection bodies and NDT service providers performing periodic cylinder and tube testing.
- Gas cylinder manufacturers and requalification centres adopting AT/UT as an alternative to hydraulic testing (with regulatory approval).
- Certifying authorities and transport safety regulators evaluating inspection methods and compliance.
- Industrial gas suppliers, fleet operators and maintenance teams managing periodic inspection programs for refillable cylinders and large tubes.
Practical benefits include targeted detection of crack‑like defects, reduced need for hydraulic proof testing where authorized, and integration into established NDT workflows (AE + UT).
Related standards
- ISO 5577, ISO 12716 (NDT vocabularies)
- ISO 6406 (periodic inspection of seamless steel cylinders)
- ISO 9712 (NDT personnel qualification)
- EN 13477 series (AT equipment characterization)
- ISO/IEC 17025, ASTM E1419, ASNT SNT‑TC‑1A (laboratory competence and practices)
Keywords: EN ISO 16148:2016, gas cylinders, acoustic emission examination, AT, ultrasonic examination, UT, periodic inspection, NDT, seamless steel cylinders, tubes.