III. Working pressure groove fittings should match the pipeline operating pressure phase. IV. For transporting hot groove fittings should be using temperature rubber seals. Rubber material for drinking water pipes should be consistent with current national standard "drinking water distribution equipment and protective materials, safety evaluation criteria" Request GB / T17219; and five pairs of lined composite steel pipe steel pipe manufacturers. When trench site processing and pipeline installation, its construction should meet the following requirements; 1 Subject Matter and Scope This standard specifies the carbon steel pipe lined with thermoplastic plastic composite pipe and fittings (hereinafter referred to as the composite pipe and pipe fittings ) product classification, technical requirements, test methods, inspection rules, marking, packaging, storage and transport. This standard applies to nominal PN1.6MPa, nominal diameter of DN25 ~ 300mm lined with polypropylene, polyethylene, ultra high molecular weight polyethylene composite pipe and pipe fittings, lined with other thermoplastic composite pipe and fittings can refer to use. Plastic pipe pressure, Jinling Industry (certified), steel pipe provided by the Hebei Golden Link Industry Co., Ltd. Hebei Golden Link Pipe Industry Co., Ltd. (www.hbjinlingpipes.com/) Hebei Hengshui, chemical products leader, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. In Jinling tube industry leadership with the staff warmly welcome all inquiries negotiations to create the Jinling tube industry a better future.