Waterproof fire closed doors, MMB waterproof closed doors of the highest quality waterproof fire closed doors available to you is my honor, our strong technical force, we believe that once you make me not like for you to create a waterproof closed doors! Sales Hotline: 15853766193 Features a waterproof fire doors closed, simple, easy to grasp the ambulance crew, the available high-pressure nitrogen gas-filled bottle, can also be artificially inflated tiger skin; 2, light weight, easy to carry; to solve the traditional enclosed material transport difficulties, consumption time-consuming work; 3, construction speed, generally only 5-7 minutes, the fastest just four minutes to complete the temporary closure; 4, good sealing effect, leakage rate, balloon air tightness, may keep without revealing more than 24h; 5, wide application, can be used in different sections of shapes, different forms of roadway bracket, versatile, very flexible; waterproof fire a closed door working environment, atmospheric pressure: 80kPa ~ 110kPa; 2, Ambient temperature: -30 ℃ ~ 40 ℃; 3, the average relative humidity ≤95% (25 ℃); 4, a methane and coal dust explosive mixture of coal mine; 5, not enough to corrode metal shell and destroy electrical insulating gas; 6, pressure: 0 ~ 3.5MPa. We re-quality heavy service! You do not regret the choice! Come on, do not hesitate