EN ISO 9809-2:2019 PDF

Overview

EN ISO 9809-2:2019 (ISO 9809-2:2019) is the European adoption of the international standard for refillable seamless steel gas cylinders and tubes made from quenched and tempered high‑strength steel (actual tensile strength Rma ≥ 1 100 MPa). The standard sets minimum requirements for material selection, design, construction, manufacturing processes, inspection and testing at time of manufacture for cylinders and tubes with water capacities up to and including 450 L used for compressed, liquefied and dissolved gases. It is part of the EN/ISO system of standards for transportable gas cylinders and replaces the 2010 edition.

Key topics and technical requirements

The standard addresses the full lifecycle of high‑strength seamless steel cylinders:

• Materials and heat treatment: minimum controls on chemical composition, required heat treatment and provisions for failure to meet material tests.
• Design: rules for cylindrical shell thickness, heads/bases (convex and concave), necks, foot rings and neck rings; limitation and verification of tensile strength.
• Manufacturing & workmanship: required wall thicknesses, surface imperfection criteria, out‑of‑roundness, straightness, mean diameter and stability checks.
• Examination and non‑destructive testing: ultrasonic examination and other inspection methods to detect defects.
• Type approval and prototype testing: procedures including tensile/hardness correlation checks, pressure cycling tests, flawed‑cylinder burst and cycle tests, base checks, bend/flattening tests and thread torque/shear stress verification.
• Batch and routine tests: tensile, impact, hydraulic bursting, proof (hydraulic) pressure, volumetric expansion, hardness and leak tests for every cylinder.
• Marking and certification: requirements for traceability and conformity assessment at manufacture.

Note: the standard excludes certain very high‑strength / large‑diameter combinations where Rma,max exceeds specified limits (e.g., Rma,max > 1 300 MPa for diameters > 140 mm with guaranteed wall thickness ≥ 12 mm, and Rma,max > 1 400 MPa for diameters ≤ 140 mm with guaranteed wall thickness ≥ 6 mm), where additional requirements may apply.

Practical applications

This standard is used to ensure safety, reliability and regulatory compliance for high‑strength seamless steel gas cylinders in industrial, medical and specialty gas sectors. Typical applications include:

• Bulk and large gas storage and transport cylinders up to 450 L
• High‑pressure gas supply for welding, chemical processes, medical gases and specialty gases
• Cylinders requiring high strength-to-weight performance where quenched and tempered steels are specified

Who uses this standard

• Cylinder and tube manufacturers designing and producing high‑strength refillable cylinders
• Quality, inspection and testing laboratories performing type approvals, batch testing and NDT
• Gas suppliers and distributors verifying supplier conformity and safety of refillable cylinders
• Regulatory bodies and certification authorities adopting harmonized requirements for transportable gas equipment
• Design and mechanical engineers specifying materials and design margins for high‑pressure containment

Related standards

• EN/ISO series for transportable gas cylinders (other parts of the ISO 9809 family and CEN/TC 23 publications) provide complementary requirements for different materials and strength classes. EN ISO 9809-2:2019 is the CEN‑endorsed version of ISO 9809-2:2019.

Keywords: ISO 9809-2, EN ISO 9809-2:2019, gas cylinders standard, refillable seamless steel cylinders, quenched and tempered, high‑strength steel, design and testing, hydraulic burst test, type approval.