Lefae is an Emitech Group laboratory that specializes in environmental testing with severe restrictions: Fire testing and combined climate testing. Based in France near the city of Lyon, the laboratory has recently acquired the qualification of a new test facility for conformity testing of equipment installed in potentially explosive atmospheres (equivalent to ATEX directives) where hydrocarbon liquids and vapors are present. Especially in the aviation industry, but also in the automotive and marine industries, conditions of potentially explosive atmospheres often prevail.
The new qualified test bench is specially designed for carrying out tests in explosive atmospheres. These tests define the requirements and procedures for aircraft equipment that may come into contact with flammable liquids and vapors. The equipment is usually connected to tank systems such as tanks, pumping systems, valves, test and control instruments. The tests are performed under normal conditions and disturbances that may occur in areas that may come into contact with flammable liquids or vapors during a flight.
Explosive capability exists when a stoichiometric air/fuel mixture is formed in such a ratio that the lower explosive limit of the mixture is exceeded. The type of mixture components and the temperature and pressure conditions under which the mixture is formed are taken into account. Flammable test liquids, vapors or gases are used to simulate the substances that are usually present in aircraft and that require oxygen for combustion.
Tests in a real environment
The tests conducted by Lefae comply with the guidelines of the EUROCAT-ED-14D, RTCA DO-160 and MIL-STD-810 standards and enable functional tests on equipment in explosive atmospheres without the need to trigger an explosion of the stoichiometric air-fuel mixture. The tests are used to assess the performance of the protective housing (ATEX directive) of the device during the test procedure in which an explosion or flame is triggered during activation of the device. The containment is characterized by the introduction of the explosive mixture and subsequent ignition. These tests also reveal temperature rises in the circuits or components, such as exhaust or hydraulic systems, as well as intermittent or permanent hotspots that can trigger an explosion of the mixture.
Lefae carries out tests in a real environment and under all climatic, mechanical, hydraulic or electrical conditions. The test table was designed according to the following specifications: a chamber volume of 450 dm3, absolute pressure at up to 12,000 meters altitude and temperatures of up to 120°C. There are sealed passages on the walls of the test chamber to accommodate controls or to power the device during the test, for example for electrical controls, the supply of liquids or for mechanical activation.
The table can also be used to study the behavior of explosive products and analyze the toxic gases of the explosion. For example, Lefae conducts studies on the thermal runaway of lithium-ion cells and batteries. Explosions and fires triggered by thermal runaway are analyzed to determine the explosion pressure and fire initiation and to analyze the toxicity thresholds of the gases produced during cell or battery failure.
A thirty-strong team of engineers and laboratory technicians support Emitech's customers in carrying out these high-risk tests. The test methods and equipment are implemented in accordance with the guidelines of the ISO 17025 standard. All measurement results and corresponding test reports are defined in accordance with the objectives and requirements of the customers and/or regulatory authorities. Emitech is the only group in France to carry out the entire testing process (climate, vibration and explosion). The company acts as a single point of contact that can anticipate and resolve failures.
