Downhole closed doors downhole closed doors, without pressure damper, fire waterproof dual gates, Jining, Shandong explosion-proof closed doors, closed doors product uses sealed door leading to the shaft bottom of the channel for the underground main substation and main drainage pumping station within, easy to turn off, to prevent the water suddenly immersed in two closed door models, specifications, technical parameters of the closed doors under pressure 98KPa. Example of the size of the cave mouth is divided into four Specification: 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) 4 MMB2.1 * 2.0 B85-373 (4) MMB1.4 * 1.8 MMB (closed doors) 1.4 (cave mouth net width 1400mm) 1.8 (net through the cave mouth height 1800mm), a closed door Product Description this closed doors for the Ministry of Coal Industry Design and Research Institute of Wuhan coal mine design, product quality standards and testing standards strictly enforce Q/WMS-3010-2005 (closed doors) four, the main structure of the closed door products a closed door doors for flat steel plate, tic-tac-toe ribs, beam group 2 door frames welded channel steel, I-beam composite frame tensioning device for tight wedge slider wedge 4 pivot bearing support the Company produces various types of fire gates, two underground explosion-proof door, closed doors, closed doors, welcome procurement