7Lively K S. Large-diameter plastic pipe mains are helping gas distri- bution[J]. Pipeline and Gas Journal, 2009, 236(12): 40-41.
8ASTM F2620-13 Standard Practice for Heat Fusion Joining of Polyethylene Pipe and Fittings[S].
9DVS 2207-I Welding of Thermoplastics Heated Tool Welding of Pipes, Pipeline Component and Sheets Made of PE-HD[S].
10ISO 21307--2011 Plastics Pipes and Fittings-Butt Fusion Jointing Procedures for Polyethylene (PE) Pipes and Fittings Used in the Construction of Gas and Water Distribution Systems[S].