Execution Standards:

MT181—1988 "Safety Performance Inspection Specification for Plastic Pipes Used in Coal Mines"

AQ1043—2009 "Safety Marking and Labeling for Mining Products"

MT558.1—2005 "Plastic Pipes Used in Coal Mines"

Part 1: Polyethylene Pipes Mining Specifications (MT558.1—2005): Surface FinishSurface resistance requirements vary depending on the application of the pipe: a) Water supply and drainage pipes: The arithmetic mean of the surface resistance of the outer wall should not exceed 10 × 10⁹ Ω b) Positive pressure air ducts: The arithmetic mean of the surface resistance of the inner and outer walls should not exceed 10 × 10⁸ Ω c) Shotcrete pipes: The arithmetic mean of the surface resistance of the inner and outer walls should not exceed 10 × 10⁸ Ω d) Negative pressure air ducts: The arithmetic mean of the surface resistance of the inner and outer walls should not exceed 10 × 10⁶ Ω e) Gas extraction pipes: The arithmetic mean of the surface resistance of the inner and outer walls should not exceed 10 × 10⁶ Ω**Alcohol Burning Test:** The alcohol burning test requirements for pipes are as follows: a) The arithmetic mean of the flaming time of 6 samples should not exceed 3 seconds, and the flaming time of any single sample should not exceed 10 seconds; b) The arithmetic mean of the flameless burning time of 6 samples should not exceed 20 seconds, and the flaming time of any single sample should not exceed 60 seconds.