CSA HGV 4.4:2013 pdf download.Standard for breakaway devices for compressed hydrogen dispensing hoses and systems
1.2.3 Breakaway devices shall be well fitted, manufactured in accordance with good engineering practice, and shall not show any signs of damage prior to commencement of the testing program. AlI specifications as to construction set forth herein may be satisfied by the construction actually prescribed or such other construction as will provide at least equivalent performance. Following the pressure technology requirements of ASME, JSME and/or the EC Pressure Equipment Directive shall be considered prima facieevidence of meeting this requirement.
1.2.6 The outlet portion of the hose breakaway device shall be designed such that separation under the pressurized condition shall either (1) allow the bleed down of gas in the hose between the breakaway and the vehicle fueling nozzle through a maximum 1 .5 mm (0.06 in) orifice, or (2) terminate the gas flow from the hose within one second.
1.3.1 Materials shall be evaluated and found to be suitable for their intended usage. Compliance is deemed met if the materials are successfully tested under Section 2.5, Material Suitability Tests or if the manufacturer supplies evidence acceptable to the testing agency for determining compliance with Section 2.5, Material Suitability Tests. Test data based on ASTM or other appropriate test procedures, certifications or historical data may be submitted for this purpose. The evidence shall show that the materials have been evaluated,as appropriate, for resistance to moisture, corrosion, temperature, the effects of fuel gases and any other compounds or conditions to which the materials may be exposed. Non-metallic seal materials shall also be suitably resistant to the effects of ozone.
1.3.2 Compressed hydrogen breakaway device(s) shall be manufactured of materials suitable and compatible for use with compressed hydrogen at the pressure and the temperature ranges to which it will be subjected. Particular attention should be given to hydrogen embrittlement, permeability and hydrogen accelerated fatigue. Materials normally in contact with hydrogen shall be demonstrated to be acceptable in hydrogen service. The material compatibility shall be documented by the component manufacturer or an independent third party.
Materials used in the construction of breakaway devices shall be made of material that is non-igniting.
Materials complying with see 2.5.4, Non-igniting Evaluation, meet this requirement.
Note: Material performance data in hydrogen environments may be found in the "Technical Reference for Hydrogen Compatibility of Materials or the Guide to Safety of Hydrogen and Hydrogen Systems.” (http://www.ca.sandia.gov/matls TechRef/)CSA HGV 4.4 pdf download.