EN 13949:2003

Overview

EN 13949:2003 is a European Standard established by CEN that sets forth the requirements, testing procedures, and marking guidelines for open-circuit self-contained diving apparatus designed for use with compressed Nitrox and oxygen. This standard applies specifically to Nitrox-SCUBA systems - underwater breathing apparatuses supplying gas mixtures containing over 22% oxygen. It supplements and expands upon the foundational EN 250 standard by addressing specialized demands and safety considerations inherent in Nitrox and oxygen use during diving.

The primary objective of EN 13949:2003 is to ensure a minimum level of safety and reliability for divers using self-contained open-circuit breathing apparatus at maximum operating depths (MODs) dictated by the Nitrox gas mix. This is achieved through comprehensive material, design, and operational requirements alongside rigorous testing protocols.

Key Topics

• Material and Design Requirements

  • Oxygen compatibility: Materials used must resist ignition and degradation when exposed to high-purity oxygen and compressed Nitrox mixtures.
  • Oxygen cleanliness: All components must be cleaned and maintained to strict oxygen use standards to prevent contamination.

• Pressure Vessels and Valves

  • Compliance with national and European regulations for pressure vessels.
  • Specific thread designs (M18 x 1.5 or M25 x 2) mandated for pressure vessel connections per EN 144-1.
  • Valves are designed to prevent inadvertent closure and protect against contamination ingress.
  • Safety features and pressure drop limits set to sustain reliable gas flow.

• Testing Procedures

  • Oxygen pressure surge tests on sub-assemblies to verify resistance to ignition risks.
  • Standardized pressure cycling with heated oxygen at 60°C and precise timing to simulate operational stresses.
  • Validation of performance under both open and closed valve states.

• Marking and Manufacturer Information

  • Sub-assemblies clearly labeled with “Nitrox”, “O2”, or “Nitrox/O2” to ensure correct use.
  • Comprehensive user warnings regarding oxygen hazards, contamination risks, and operating limits.
  • Recommendations for training and maintenance to maximize safety.

Applications

EN 13949:2003 targets manufacturers, testers, and end-users within the diving industry engaged with the design, production, and deployment of Nitrox and oxygen SCUBA equipment. The standard serves multiple practical purposes:

• Diving Equipment Manufacturers

  • Guiding product design and material selection to meet oxygen compatibility and cleanliness criteria.
  • Implementing standardized testing to comply with EU regulatory frameworks and ensure market acceptance.

• Diving Operators and Training Centers

  • Ensuring equipment provided to divers is compliant with recognized safety standards.
  • Educating divers on the risks associated with oxygen-enriched breathing gases and the importance of proper equipment handling.

• Safety Inspectors and Certification Bodies

  • Using the standard as a benchmark for equipment certification and periodic safety inspections.

• Recreational and Professional Divers

  • Relying on certified apparatus to mitigate risks related to maximum operating depths, oxygen toxicity, and contamination.

By aligning with EN 13949:2003, stakeholders can enhance diver safety, equipment reliability, and regulatory compliance, thus promoting safer underwater operations using Nitrox and oxygen-based breathing apparatus.

Related Standards

EN 13949:2003 complements and references several other critical European standards in breathing apparatus and diving equipment:

• EN 250:2000 – Respiratory equipment – Open-circuit self-contained compressed air diving apparatus – Requirements, testing, marking. Forms the base standard supplemented by EN 13949 for Nitrox use.
• EN 132:1998 – Respiratory protective devices – Definitions of terms and pictograms.
• EN 144-1 & EN 144-3 – Respiratory protective devices – Gas cylinder valves thread and outlet connections for diving gases such as Nitrox and oxygen.
• EN 12021 – Respiratory gases – Requirements for the supply of breathing air for respiratory protective devices, relevant as a caution about contamination sources.

Additionally, EN 13949:2003 supports compliance with essential health and safety requirements outlined in EU Directive 89/686/EEC concerning personal protective equipment (PPE), including ergonomic and safety performance criteria for respiratory devices under hazardous conditions.

By adhering to EN 13949:2003, manufacturers and users of Nitrox and oxygen self-contained open-circuit diving apparatus can ensure high standards of safety, functionality, and regulatory conformity, critical for modern underwater breathing systems design and operation.