3. Flange pressure rating should match the working pressure pipeline phase. Second plastic composite pipe flange connection site shall meet the following requirements: 1. plastic composite pipe cut pipe shall comply with the requirements of this Regulation 6.2.1; 2. at the scene connected with wear-resistant high-pressure polyethylene pipe flange steel Plastic pipe should be used within a convex lined steel pipe flanges with neck; 3 should be twisted thread sealing pipe thread knitting resistant steel pipe steel pipe with a plastic composite pipe is connected, the tooth type should be consistent current national standard "with thread sealing pipe thread" requirement GB / T7306; and when four plastic composite pipe flange connections when using the second installation method, on-site installation of pipe, fittings, valves and flanges should be marked Seal number. General provisions threaded flange connection trench inspection and acceptance testing and acceptance of a experimental pressure plastic composite pipe water supply piping system should be used with ordinary steel the same experimental pressure water system. II. Plastic composite pipe system pressure test program consistent with ordinary steel pipe systems. Wear-resistant high-pressure steel pipe, steel pipe, provided by Golden Link Pipe Industry Co., Ltd. Hebei Golden Link. Hebei Golden Link Pipe Industry Co., Ltd. (www.hbjinlingpipes.com/) strong, credible, Hebei Hengshui chemical products industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead the Golden Link Pipe and you work into the brilliant, for a better future!