Products the channel leading to the main substation and the main drainage pumping station in the coal mine shaft bottom, easy to set off, and both waterproof and can fire closed doors. Economic Ninghao Bo mining mine sells a variety of doors, welcome new and old customers to inquire Haobo sincerely look forward to working with you! Main features: All steel welding, beautiful and practical, easy to install, easy to maintain. Second, the working conditions, the atmospheric pressure: 80kPa ~ 110kPa; 2, ambient temperature: -30 ° C to 40 ° C; 3, the average relative humidity ≤ 95% (25 ° C); 4, an explosive mixture of methane and coal dust coal mines underground; 5, no sufficient corrosion damage the metal casing and electrical insulation gas; 6, pressure: 0 ~ 3.5MPa. Third, the mine closed doors main structure a closed door doors for flat steel, tic-tac-toe ribs, beam group welded wedge slider 2 door frame channel steel, I-beam composite frame tensioning device 4 wedge pivot bearing support, model specifications, the technical parameters of the closed door to withstand the maximum pressure 98KPa. Specification example is divided into four cave mouth size: No. Model Specification Drawing No. 1 MMB1.4 * 1.8 B85-373 (1) 2 MMB1.6 * 1.8 B85-373 (2) 3 MMB1.8 * 2.0 B85-373 (3) MMB2.1 * 2.0 B85-373 (4) MMB1.4 * 1.8 MMB (closed doors) 1.4 (net cave mouth through the width of 1400mm) 1.8 (net cave mouth by height 1800mm)