BS 6391:2009 pdf free download – Specification for non-percolating layflat delivery hoses and hose assemblies for fire fighting purposes.
8 Type tests
8.1 Hydrostatic tests
8.1.1 Dimensional stability
When the hose is tested in accordance with Annex C:
a) the length contraction of the hose when the pressure is first increased to 0.7 bar shall not exceed 1 % of the reference length of the unpressurized test piece;
b) the increase in length, when the pressure is increased from 0.7 bar to 12 bar, shall not exceed 5% of the length measured originally at 0.7 bar, and the increase in outside diameter shall not exceed 10% of the original diameter;
c) the residual increase in length, determined when the pressure is returned to 0.7 bar, shall not exceed 1 % of the length measured originally at 0.7 bar.
8.1.2 Kinked test piece under pressure
When tested in accordance with Annex D, the test piece shall neither burst nor show any visible signs of defect.
8.1.3 Burst pressure
When tested in accordance with BS EN ISO 1402, the average value of the burst pressure for five test pieces shall be not less than 45 bar and no individual result shall be less than 43 bar for hoses up to and including 76 mm. For 89 mm diameter test pieces, the average burst pressure shall be not less than 35 bar and no individual result shall be less than 33 bar.
8.2 Adhesion
When tested in accordance with Annex F, the rate of separation of the lining and reinforcement and, for type 3 hoses, the rate of separation of the cover and reinforcement, shall not exceed 25 mm/rn in.
8.3 Moisture absorption (types 2 and 3 only)
When tested in accordance with Annex F, the amount of moisture absorbed shall not exceed 0.17 kg/rn2 for type 2 hoses and 0.02 kg/rn2 for type 3 hoses.
NOTE The resistance of fire hoses to acids and alkalis has been found to relate to their resistance to moisture absorption, thus type 3 hoses can be expected to have the greatest resistance to acids and alkalis.
8.4 Flexibility
8.4.1 At a temperature greater than 5 °C, the hose shall be capable of being laid in flakes (see Figure 1) of 2 m length and coiled into a smooth roll without any straight sections.
8.4.2 After conditioning at —20 °C ± 1 °C for 24 h ± 1 h, a dry, rolled length of not less than 15 m of hose shall be capable of being unrolled immediately. After the hose has been unrolled and immediately folded back on itself through 1800, it shall withstand, without any sign of leakage, a proof pressure of 22.5 bar maintained for 1 mm, in accordance with BS EN ISO 1402.
8.5 Heat ageing
8.5.1 Six 1 m lengths of hose shall be conditioned for 120 h at 20°C ± 2 °C and 65% ± 2% relative humidity, and then aged for 336 h at 70 °C ± 2 °C. After ageing, there shall be no tackiness of the surface of the lining or, for type 3 hoses, of the surface of the cover.
8.5.2 Five of the 1 m lengths of hose aged in 8.5.1 shall then be subjected to a burst pressure test in accordance with BS EN ISO 1402. The average value of the burst pressure for five test pieces shall be not less than 35 bar and no individual result shall be less than 33 bar.
8.5.3 The remaining 1 m length of hose aged in 8.5.1 shall be tested in accordance with Annex E. The rate of separation of the lining and reinforcement and, for type 3 hoses, the rate of separation of the cover and reinforcement, shall not exceed 25 mm/min.