B.4A.3 Independent fire test
Non-metallic petrol tanks if tested independently shall use the test method described in B. 5.
B.5A.4 Test method - Independent fire test
B.5.1 The area in which the test is to be conducted shall be free from draughts but shall allow a free inflow of air during the test.
B.5.2 Perform a pressure test according to Annex A. The tank to be tested shall show no leakage. Release the test pressure.
B.5.3 Centre, position and fasten the tank, with the fasteners used in craft, vertically 75 mm above the liquid surface of a pan with sides extended 150 mm beyond the vertical sides of the tank to be tested.
The pan shall accommodate enough commercial heptane to burn continously for at least 2,5 min.
B.5.4 Fill the tank to be tested to 25 % of its rated, or full, capacity with petrol.
All openings shall be capped or plugged, exept for fuel tank ventilation that is to be extended without straps, outside the fire test areas.
B.5.5 The commercial heptane in the pan shall be ignited and permitted to burn for a continous period of 2,5 min.
B.5.6 At the end of the 2,5 min test period, any continued burning shall be extinguished.
B.5.7 Examine the sample tank for leakage. Drain the tank. Pressure-test the tanks with a slowly increased air or inert gas pressure up to 2 kPa.
The tank shall show no evidence of leakage when checked with methods other than the pressure drop method (see A.4).
WARNING - LARGE FLAMES AND BURNING WASTE FUEL MAY OCCUR AT LEAKAGE. THEREFORE THE TEST SHALL BE PERFORMED IN A NON-COMBUSTIBLE ENVIRONMENT AND WITH PERSONNEL EQUIPPED WITH PROTECTIVE AND FIREFIGHTING EQUIPMENT.
