ISPESL or PED certified welded steel structures manufacture. Sloping filling door for easier metal pouring and bath scraping. Automatic filling door optional device. Refractory material lining with low heat transmission. Seal with the mold assured by the lifting system with springs compensation. Orizontal translation done by hydraulic cylinder or ratio-motor. Heating with armoured resistances placed on the lid. Pressurization system with proportional control and exaust air heat exchanger.