1. convex plate flat welding steel pipe flanges should comply with national standards, "convex plate flat welding steel pipe flanges" requirement GB / T9119.5 ~ 9119.10; and 2. convex steel pipe flanges with neck should comply with national standards, "convex steel pipe flanges with neck" GB / T9114.1 ~ 9114.3 requirements apply only to the nominal diameter of not more than 150mm plastic composite pipe connections; Three plastic composite tube method Lan connection can be taken according to the construction workers on the skill of the first installation method or the second installation method: 1. first installation method: Field measurements, rendering pipeline processing single line diagram PF wearable wire braided composite pipe steel pipe, the pipe section to send a professional factory non-ferrous ore steel pipe steel pipe series, accessories painted (lining) processed coil steel pipe steel pipe series, and then delivered to the site for installation; 2. the second installation method: in the field of non-coated (lining) Pipe and pipe fittings, flanges, welding, assembling the pipe, and then remove the plants were delivered to professional coating (lining) processing, and then delivered to the site for installation. High-pressure steel pipe steel pipe series steel pipe _ _ Golden Link Pipe by 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!