Our produced piping is the coal mine polyethylene pipe (KM, hereinafter referred to as piping), suitable for underground water supply and drainage, concrete spraying, positive pressure ventilation, negative pressure ventilation, and gas drainage in coal mines. The reference working temperature for the piping is 20°C, with a working temperature range of -10°C to +40°C. There is a pressure reduction coefficient between 20°C and 40°C, and the working pressure is the nominal pressure multiplied by the pressure reduction coefficient. The piping used for gas drainage purposes must have a nominal pressure of not less than 1.0MPa.