BS EN ISO 17871:2020 pdf download.Gas cylinders — Quick-release cylinder valves — Specification and type testing.
4 Requirements
4.1 General requirements Quick-release cylinder valves shall comply with all requirements of ISO 10297, unless this document expressly allows differing requirements or stipulates additional requirements. It is the responsibility of the manufacturer to classify the type of the quick-release cylinder valve according to the definitions in 3.2 (type A) or 3.3 (type B, C, D, or E) and to declare if the quick-release cylinder valve is designed for intermittent or total discharge. For type A valves for auxiliary refillable propellant gas cylinders with a water capacity of not more than 1,5 l, and where each filling requires the replacement of the valve operating mechanism, the material requirements for the valve body given in ISO 10297:2014+Amd.1:2017, 5.2, do not apply because for such designs the neck of the cylinder acts as the valve body.
4.2 Differing/additional requirements
4.2.1 Valve connections Differing from the requirements given in ISO 10297:2014+Amd.1:2017, 5.4, if the valve filling connection is separate from the valve outlet connection, the relevant requirements for the endurance test of the separate filling connection closure device given in ISO 22435 shall be met, but the number of endurance cycles for the filling connection closure device shall be as specified by the manufacturer. For type A valves, if the non-return valve in the separate valve filling connection does not require to be replaced after each operation, it shall be subjected to a number of endurance test cycles to be specified by the manufacturer.
4.2.2 Resistance to mechanical impact Differing from the requirements given in ISO 10297:2014+Amd.1:2017, 5.5.2, quick-release cylinder valves need not remain capable of being opened for emergency venting purposes if the quick-release cylinder valve has a means of safely venting the gas contents. After the impact test, the securing arrangements used shall still ensure the quick-release cylinder valve does not open.
4.2.3 Valve operating mechanism Differing from the requirements given in ISO 10297:2014+Amd.1:2017, 5.6.3, the number of endurance cycles is given in Table 1.
4.2.4 Valve operating device The requirements given in ISO 10297:2014+Amd.1:2017, 5.7, are not applicable, except for the requirement for the handwheel diameter.
4.2.5 Leakage Differing from ISO 10297:2014+Amd.1:2017, 5.8, the total external leakage (if to be tested, see 4.2.9) shall not exceed 12 cm 3 /h.
4.2.8 Valve test pressure In addition to the requirements given in ISO 10297:2014+Amd.1:2017, 6.6.2, p vt for extinguishing agents charged with compressed gases shall be at least the developed pressure of the filled cylinder at 65 °C. The developed pressure at 65 °C shall be calculated depending on the compressed gas and its maximum filling pressure at a given filling temperature as well as maximum filling ratio. The vapour pressures and volumetric expansion of all substances in the cylinder shall be taken into account. NOTE 1 Liquid phase expansion coefficients and vapour pressures are, for example, available from NIST databases 1) or from fire-extinguishing agents manufacturer's data sheets. NOTE 2 The calculation method is given in packing instructions P 200 and P 206 of the UN Model Regulations [1] . If available, experimental data for the developed pressure at 65 °C taking the solubility of the compressed gas into account may be used instead of calculated data. BS EN ISO 17871 pdf download.