Flat welding flange connection is generally used in the pipeline, in that case, loosen the bolt can rotate the pipeline on both sides, and then tighten it can be more convenient to disassemble the pipeline.The material is carbon steel flange called carbon steel flange;Flat welding flange connection method is also the simplest connection method between cast iron pipe and steel pipe.The French blind plate can be used to inspect the opening of the mouth.Flanged connection is suitable for pipe fittings with diameter from Φ50 to 315mm.Matching flange its performance characteristics: non - rigid connection, dismountable, tensile resistance.Flanged joints are usually used as removable fittings in low pressure transmission lines.