Our company produces polyethylene pipes (KM) for coal mine use (hereinafter referred to as pipes), which are suitable for water supply and drainage, slurry spraying, positive pressure ventilation, negative pressure ventilation, and gas drainage in coal mine shafts. The reference working temperature for the pipes is 20°C, with an operating 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 pipes used for gas drainage must have a nominal pressure not less than 1.0MPa.