Common use of Equivalent test methods Clause in Contracts

Equivalent test methods. 3.1. Equivalent test methods are permitted provided that the conditions referred to in this Regulation can be observed either entirely by means of the substitute test or by calculation from the results of the substitute test. 3.2. If a method other than that described in paragraph 2. above is used, its equivalence must be demonstrated. TESTING OF FUEL TANKS MADE OF A PLASTIC MATERIAL 1. COLLISION RESISTANCE 1.1. The tank must be filled to its capacity with a water-glycol mixture or with another liquid having a low freezing point, which does not change the properties of the tank material, and must then be subjected to a perforation test. 1.2. During this test the tank temperature must be 233K " 2K (- 40 °C " 2 °C). 1.3. A pendulum collision testing fixture must be used for the test. The collision body must be of steel and have the shape of a pyramid with equilateral-triangle faces and a square base, the summit and the edges being rounded to a radius of 3 mm. The centre of percussion of the pendulum must coincide with the centre of gravity of the pyramid; its distance from the axis of rotation of the pendulum must be 1 m. The total mass of the pendulum must be 15 kg. The energy of the pendulum at the moment of collision must be not less than 30 Nm and as close to that value as possible. 1.4. The tests must be made on the points of the tank which are regarded as vulnerable to frontal or rear collisions. The points regarded as vulnerable are those which are most exposed or weakest having regard to the shape of the tank or the way in which it is installed on the vehicle. The points selected by the laboratories must be indicated in the test report. 1.5. During the test, the tank must be held in position by the fittings on the side or sides opposite the side of collision. No leak must result from the test. 1.6. At the choice of the manufacturer, all the impact tests may be carried out on one tank or each may be carried out on a different tank.