BS 3-8:2006 pdf download – 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
The test pressure PT’ shall not be less than 1,43 times the maximum allowable pressure Ps with a minimum of20 bar.
The test pressure shall be maintained for a minimum of 30 s and the body shall remain tight.
After the test, the volume of the body shall not increase by more than 1 %.
6.3.4.3Requirements – Fittings
The test pressure PT shall not be less than 1,43 times the maximum allowable pressure Ps with a minimum of20 bar.
The test pressure shall be maintained for a minimum of 30 s and the fittings shall remain tight and show nodangerous defect.
6.3.4.4Requirements – Assembly
The test pressure PT shall not be less than 1,43 times the maximum allowable pressure PS with a minimum of20 bar.
The test pressure shall be maintained for a minimum of 30 s and the assembly shall remain tight and show nodangerous defect.
6.3.5 Pressure test – Pressure gauges and pressure indicators
6.3.5.1 Test conditions
Five samples shall be submitted to the pressure test which shall be carried out using apparatus that permits aregular increase of pressure at a maximum of 2 barls until 2,5 times P(Tmax) is reached. Maintain this pressure for30 s.
6.3.5.2 Requirements
When tested at a temperature of (20±5)°C, the sample shall not leak at a pressure less than 2,5 times P(Tmax)-
Failure shall occur at a pressure greater than 2,5 times P(Tmax) and when the gauge fails there shall be no ejectionof any components.
NOTE This test should be considered to be a destructive test.
6.3.6Macroscopic examination of the body
On five bodies each weld subject to pressure shall be examined, the macroscopic examination of a transversesection of the weld,in accordance with EN 1320，shall show complete fusion over the area treated with apreparation acid and any defects shall be revealed.
lf there is any doubt, a microscopic examination of the suspect area shall be carried out.
6.3.7 Plastics components
Plastics components shall comply with the requirements of Annex D.
6.4Overfill pressure test (for water based media cartridge operated extinguishers only)
To make sure the extinguishers will remain safe even in case of overfilling, the extinguishers shall be tested inaccordance with Annex G and shall not eject any components in a dangerous manner. This test shall beperformed on two samples.
6.5Resistance to impact6.5.1 Test conditions
TSmax and TSm.in claimed by the manufacturer shall be used for the tests in 6.5.2 and Annex C.6.5.2 Requirements
When tested in accordance with Annex C, extinguishers shall not show evidence of bursting, breakage or ejectionof components. Non-dangerous leaks are acceptable.
7 Manufacturing
7.1General requirements
The manufacturer shall ensure that he has available the manufacturing means and processes suitable forfabricating the bodies in accordance with this European Standard.
The manufacturer shall ensure that the materials and components used in the fabrication of the body are free fromany defect likely to impair the safe use of the extinguisher.
7.2welded and brazed parts
7.2.1General
Pressure bearing welds shall be formed using an automatic welding procedure.
Welds and brazed joints shall be free from defects which may impair the safe use of the body.
7.2.2Welding procedures
The welding procedures shall be based on a welding procedure specification in accordance with EN ISO 15614-1or EN lSo 15614-12 and shall be qualified in accordance with EN ISO 15614-1 or EN ISO 15614-12 orEN ISO 15614-2.
Other recognised welding EN standards are acceptable.
7.2.3Welding personnel
The welders shall be qualified in accordance with EN 287-1 or EN ISO 9606-2 and the operators in accordancewith EN 1418.
7.2.4Brazing procedures
The brazing design and brazing procedure shall be described in a brazing procedure specification in accordancewith EN 13134.BS 3-8 pdf download.