Lefae is qualified for testing in an explosive atmosphere

Lefae’s new bench is designed, for carrying out tests in an explosive atmosphere. These tests specify the requirements and procedures for aircraft equipment which could come into contact with flammable fluids and vapours. This equipment is generally associated with fuel systems, such as tanks, pump units, valves, monitoring and control instruments, etc. This type of test encompasses both normal and fault conditions, potentially occurring in zones that are or may be in contact with flammable fluids and vapours during flight operations.

Real Environment

The tests performed by Lefae comply with the requirements of EUROCAT-ED-14D, RTCA DO-160, MIL-STD-810 standards. They enable functional tests to be run on the equipment in an explosive atmosphere without triggering the explosion of the stoichiometric air/fuel mixture. They evaluate the capacity of the protective enclosure (ATEX requirement approach) of the equipment under test to contain an explosion or a flame when the equipment is activated. The characterization of the containment is then carried out by introducing the explosive mixture and then triggering it. The test also reveals overheating of the circuits or components in hydraulic or exhaust systems for example, and intermittent or permanent hotspots capable of triggering the explosion of the mixture.

Lefae carries out tests in a real environment and all climatic, mechanical, hydraulic or electrical conditions. The test bench has been designed, to the following specifications: the chamber volume is 450 dm3, absolute pressure conditions up to 12,200 meters (40,000 feet) in altitude, temperatures up to 120°C (248°F). Sealed passages are available in the walls of the test chamber to accommodate controls or supply to the equipment under test, for example, electrical controls, fluid supply or mechanical activation.

The bench can also be used to investigate the behaviour of intrinsically explosive products and analyse the toxic gases resulting from their explosion. For example, Lefae conducts studies on the thermal runaway of Lithium Ion cells and batteries. Explosions and fires triggered by thermal runaway are analysed to determine the explosion pressure, the fire ignition and to analyse the gases toxicity level produced during cell or battery failure.