Overview
EN ISO 407:2023 - titled Small medical gas cylinders - Pin-index yoke-type valve connections (ISO 407:2023) - specifies dimensional and design requirements for pin-index yoke-type valve connections used on small medical gas cylinders. It applies to cylinders with a working pressure up to 200 bar or a test pressure up to 300 bar, and is primarily intended for small cylinders (approximately 5 L or below). The document defines basic dimensions, alternative yoke designs, and the exact positions and dimensions of holes and pins for a range of medical gases and gas mixtures.
Key topics and technical requirements
- Basic dimensions: Standardised geometric features for yoke-type valve bodies and connecting yokes to ensure reliable mating between cylinder valves and yokes.
- Pin and hole locations: Precise positions and sizes of pins and valve holes for outlet connections - critical for preventing cross-connections of different medical gases.
- Alternative designs: Requirements and permitted variations for alternative yoke constructions while maintaining functional compatibility and safety.
- Gas allocation table: Specific pin-hole configurations for gases and mixtures such as oxygen, medical air, nitrous oxide, carbon dioxide, helium, ethylene, cyclopropane, nitrogen and defined mixtures (e.g., oxygen/helium, oxygen/carbon dioxide).
- Marking and identification: Requirement that the gas name or chemical symbol be clearly and indelibly stamped on both the valve and the yoke; colour identification may follow ISO 32 conventions.
- Pressure scope: Applies to systems with working pressures ≤ 200 bar or test pressures ≤ 300 bar (note: the document uses bar units; 1 bar = 10^5 Pa).
Practical applications
- Ensures interchangeability and safety of small medical gas cylinders and yoke valves used in hospitals, ambulances, dental clinics, and field medical kits.
- Prevents accidental gas misconnections by standardising pin-index safety arrangements for different gases and mixtures.
- Guides manufacturers of cylinder valves, yokes and pressure regulators in producing compliant components for markets adopting CEN/ISO standards.
- Supports procurement, maintenance and inspection teams by providing acceptance criteria for replacements and retrofit parts.
Who should use this standard
- Cylinder and valve manufacturers
- Medical-device and anaesthesia-equipment designers
- Hospital biomedical engineering and procurement teams
- Testing laboratories and conformity assessment bodies
- Regulatory authorities and standards committees
Related standards
- ISO 32 (Gas cylinders for medical use - Marking for identification of content) - referenced normative document for gas identification.
EN ISO 407:2023 is a harmonised specification for safe, standardised pin-index yoke-type valve connections on small medical gas cylinders, promoting compatibility, patient safety and regulatory compliance across healthcare and transportable gas cylinder applications.
