BS EN 3-9-2006 pdf download.Portable fire extinguishers Part 9: Additional requirements to EN 3-7 for pressure resistance of CO2 extinguishers.
This BS EN 3-9 specifies the rules of design, assembling, inspection and testing of CO2 portable fire extinguishers as far as the pressure risk is concerned.
NOTE Annex A gives the classification of the different parts forming the assembly of the portable extinguisher.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references. only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 3-7:2004, Portable fire extinguishers — Part 7: Characteristics, performance requirements and test methods
EN 3-8:2006, Portable fire extinguishers — Part 8: Additional requirements to EN 3-7 for the construction, resistance to pressure and mechanical tests for extinguishers with a maximum allowable pressure equal to or lower than 30 bar
EN 629-1:1996, Transportable gas cylinders — 25E taper thread for connection of valves to gas cylinders — Part 1: Specification
EN ISO 11116-1:1999, Gas cylinders — I 7E taper thread for connection of valves to gas cylinders — Part 1:
Specifications (ISO 11116-1:1999)
EN ISO 15245-1:2001, Gas cylinders — Parallel threads for connection of valves to gas cylinders — Part 1:
Specification (ISO 15245-1:2001)
ISO 6718:1991, Bursting discs and bursting disc devices
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 3-7:2004, EN 3-8:2006 and the following apply.
3.1
filling ratio
maximum allowable fill measured in kgIl
4 Materials
4.1 General
There is a relationship between the filling ratio, the maximum allowable pressure and the maximum allowable temperature depending on the pressure-temperature curves of carbon dioxide. Commonly used filling ratios are 0,667, 0,675 and 0,750, and the corresponding maximum allowable pressures at 60 °C are shown in Annex B.
5.3 Operating device
The operating device is a pressure accessory that can be fitted with the bursting disc.
The thread of the operating device shall be in accordance with Annex C and shall be stamped, engraved or
embossed with the specified code.
5.4 Bursting disc
Extinguishers shall be fitted with a bursting disc, which shall comply with ISO 6718.
The bursting disc at ± 2) °C shall operate at a pressure between 1,1 PS and the test pressure of the extinguisher PT, Including all manufacturing tolerances.
NOTE PS of the extinguisher assembly cannot exceed the PS of any component of the extinguisher assembly.
5.5 Hose and nozzle couplings — Prototype testing
5.5.1 Requirements
The coupling systems given below shall function throughout the operating temperature range of the fire extinguisher. Coupling systems shall be designed and fitted in such a way that they cannot damage the hose. The burst pressure shall be equal to or greater than the appropriate value below when tested in accordance with 5.5.2.
1,5 times the pressure developed at the test being carried out at (20 ± 5) °C — one specimen.
1,25 times the pressure developed at Tma, the test being carried out at (T11 ± 5) °C — two specimens:
operating device/horn — operating device/hose:
— operating device hose/horn — operating device horn/nozzle.
5.5.2 Test conditions
The burst pressure shall be established by increasing the pressure to the minimum allowable burst pressure In a time not less than 30 s maintaining that pressure for a further 30 s during which failure shall not occur and then increasing the pressure at a maximum average rate of 10 bar/s until the point of failure.
The compatibility between the thread of the ct1inder and the thread of the operating device shall be checked.
The manufacturers declared torque between the operating device and the cllnder and the operating device and the bursting disc shall be utilised.
Manufacturing process shall be defined and controlled and shall not adversely affect the design characteristics.
The identification and the traceability of the materials for all pressure retaining parts shall be ensured by the manufacturer after reception of these materials. This is realised by application of adequate procedures, internal to the manufacturer, such as batch control traceability.
7 Final assessment of the assembled extinguisher
7.1 General
The evaluation of the integration of the different parts of the extinguisher shall be checked by:
— document basis at the design stage;
— the duration of operation shall be as follows:
a) at T duration of operation shall not be more than the value established at a temperature of + 20 °C:
b) at Tmjn duration of operation shall not be more than 2,5 times the value established at + 20 DC. Compliance shall be demonstrated using an appropriate sampling plan.
7.2 Validation of accessories
Fittings (excluding bursting disc subject to pressure shall meet the following requirements. For fittings in Category I or article 3 § 3 of Directive 97123/EC, compliance shall be demonstrated by pressure testing components selected from production using an adequate sampling plan.
All fittings (excluding bursting disc) in Category II or higher shall be submitted to a pressure test. The test pressure PT shall not be less than 1.43 times the maximum allowable pressure PS.
The test pressure shall be maintained for a minimum of 30 s and the fittings shall remain tight and show no dangerous defect.
Fittings include operating devices, hose assemblies. The fittings need not be tested as part of the complete extinguisher but the test equipment connection and blanking features shall replicate the adjacent components.BS EN 3-9-2006 pdf download.