Fire extinguishing cover for concrete pit under electrical transformer with baffles plates EXTICOV-LHD

with natural flame extinction

EXTICOV-LHD® covers consist of prefabricated frames made of LHD® fire-retardant gratings. The various elements are welded together to form panels. These are then installed in the upper part of the pit on specially designed angles, forming a 3-in-1 perforated structure floor: fireproof, anti-slip and handling area. Once the hot oils are "trapped" in the pit, the fire self-extinguishes almost instantaneously due to the lack of renewal of the oxygen oxidizer. As the smothering phenomenon is very rapid, the temperature rise inside the pit is low, making thermal runaway, which could accelerate the spread of the fire, almost impossible. The device thus acts passively and simultaneously on 2 of the 3 components of the fire triangle in a simple and effective way: temperature and oxygen oxidizer. Technical features: 500 daN/m² load distributed over 200×200 mm, in accordance with EN-14122, of 1.5 kN. Hot-dip galvanized steel with a recommended minimum thickness of 3 mm to guarantee a deflection of less than 4 mm as per EN-14122. Possibility of additional surface treatment with GALVAGRID® zinc coating for an anti-corrosion equivalent equal to or better than C5H or C5X. Maximum permissible air passage of approx. 4.1% to ensure sufficient watertightness to prevent oxygen renewal under the pit. Diameter of perforation holes 7mm, approx. 1065 holes per m², i.e. approx. 4.1% of the surface is open. Minimum flow rate approx. 660 L/min for mineral oil at a temperature of 90°C through 1 m² of cover.