ISO/TR 16115:2013 PDF

Overview

ISO/TR 16115:2013 is a Technical Report from ISO/TC 58 that defines a practical procedure for the visual evaluation and classification of manufacturing imperfections on seamless steel and aluminium-alloy gas cylinders at the stage of product acceptance. It provides a normative Annex A with a template of common defects, inspection conditions and acceptance/rejection criteria intended for incorporation into cylinder design standards (e.g. ISO 9809‑1/2/3 for seamless steel and ISO 7866 for seamless aluminium alloy cylinders).

Key topics and technical requirements

• Scope and purpose
  • Establishes how to evaluate the most commonly found manufacturing imperfections during final visual inspection.
  • Provides a template for inclusion in cylinder design standards and guidance to implement into other standards.
• Inspection conditions
  • Visual inspection must be made on a clean, dry product under good lighting; internal inspection may use a scope or mirror; magnification can be used but final assessment is as if no magnification were used.
  • Thicker cylinder sections may allow proportionally larger absolute imperfection sizes provided safety is not compromised.
• Classification of imperfections
  • Imperfections are categorized into Level 1 (acceptable), Level 2 (reject - repairable), and Level 3 (reject - not repairable / render unserviceable).
  • Examples (from Annex A tables) include bulges, dents, cuts/gouges, laminations, blisters, cracks, neck/tap marks, internal folds and excessive grinding.
  • Numeric guidance is provided for common cases (e.g., dent depth and diameter relationships, limits on cut/gouge depth relative to guaranteed minimum wall thickness).
• Repair and disposition
  • Small permitted imperfections may be removed by dressing/grinding provided remaining wall thickness meets the guaranteed minimum. Level 2 items can be repaired and re‑inspected; Level 3 items must be rendered unserviceable (see ISO 6406 for methods).
• Process tools
  • Includes a flow diagram for final visual inspection and normative tables (A.1–A.4) for safety‑related and cosmetic imperfections.

Practical applications and users

• Primary users: cylinder manufacturers, quality inspectors, production supervisors, OEMs and inspection bodies involved in gas cylinder acceptance testing.
• Secondary users: regulatory authorities, certification and testing laboratories, repair shops and procurement teams specifying acceptance criteria.
• Benefits: harmonized acceptance criteria, clearer repair/removal rules, reduced disputes at product acceptance, and consistent incorporation into cylinder design standards.

Related standards

• ISO 9809-1, ISO 9809-2, ISO 9809-3 - seamless steel cylinder design standards
• ISO 7866 - seamless aluminium alloy cylinder design standard
• ISO 6406 - examples of methods to render cylinders unserviceable

Keywords: ISO/TR 16115, gas cylinders, manufacturing imperfections, visual inspection, defect classification, seamless steel cylinders, aluminium alloy cylinders, acceptance criteria, cylinder design standards.