ISO 21969:2009: high-pressure flexible connections for medical gases

Scope

According to the ISO abstract, the standard applies to high-pressure flexible connections intended to be connected to cylinders or cylinder bundles with nominal filling pressures up to 25 000 kPa at 15 °C. It covers two uses: connecting cylinders or bundles to manifolds within the sources of supply of medical gas pipeline systems complying with ISO 7396-1, and connecting a cylinder to an inlet port of medical equipment, such as an anaesthetic workstation or lung ventilator, fitted with an integral pressure regulator complying with ISO 10524-1.

The gases listed are oxygen, nitrous oxide, air for breathing, helium, carbon dioxide, xenon, mixtures of these gases, air and nitrogen for driving surgical tools, and oxygen-enriched air.

Edition and status

• Edition 2, published in November 2009, 13 pages, prepared by ISO/TC 121/SC 6. It replaced ISO 21969:2005, which ISO lists as withdrawn.
• On 23 October 2026 the ISO page showed stage 90.93 (International Standard confirmed): the publication was last reviewed and confirmed in 2022, so this version remains current. ISO reviews its standards every 5 years.
• NHS England's HTM 02-01 (2026) cites it as BS EN ISO 21969:2009.

How hospital guidance uses it

• HTM 02-01 Part B (2026), 4.18, describes the standard as applying to the flexible connections used to connect medical gas cylinders to manifolds, and says it states that non-metallic hoses should not be used, in addition to requirements for gas-specific connections and ignition and other safety-related items.
• SHTM 02-01 Part A (NHS Scotland, Version 2, August 2026) states that cylinder manifold tailpipes manufactured to ISO 21969 will provide a flow of 83 litres/min when the cylinders are nominally empty (20 bar(g)) (5.131), and that ISO 21969 specifies that the flexible hose for cylinder packs should be rated at 830 litres/min gas flow when the pack drops to nominally empty contents (5.136).
• The 2020 WHO interim specification for PSA oxygen plants, which WHO's December 2024 specifications supersede, listed ISO 21969 among its product performance standards.

Tailpipes in manifold design and maintenance

Under HTM 02-01 Part A (2026), 5.33, manifold headers should incorporate a replaceable check valve to prevent discharge of a complete cylinder bank in the event of tailpipe rupture. The maintenance tasks for automatic manifolds in Part B (11.170) include isolating one cylinder in turn and disconnecting the tailpipe to check its non-return valve: a minor weep is permissible and likely, but an obvious major leak denotes failure of the valve. The tasks for manual emergency reserve manifolds (11.168) include the same check.

Related standards

ISO 7396-1 covers the pipeline system and its sources of supply, and ISO 10524 covers pressure regulators. Low-pressure hose assemblies are a separate standard, ISO 5359, which HTM 02-01 Part B lists on its own (4.17).