How to do a good job in passivation treatment of large blind flange

　　The passivation process of large blind flange can be divided into wet method and dry method. It can be divided into many types. The passivation of large blind flange depends not only on the passivation process, but also on the material of large blind flange. The specific influencing factors include the elements contained in the large blind flange, the metallographic structure of stainless steel, and the processing state of stainless steel. Among the constituent elements, chromium and nickel belong to the elements with strong passivation, followed by iron. Therefore, the higher the content of chromium and nickel, the stronger the passivation of stainless steel. Austenitic and ferritic type large blind flange has uniform structure and good passivation property. Martensitic stainless steel is multiphase structure after heat treatment, so passivation is not strong.

　　After machining, the smooth and smooth surface of large blind flange has good passivation, and the workpieces obtained by forging and sandblasting are rough and dry, which is bad for passivation.

　　Large blind flange material not only has a qualified creep rupture curve, but also its pipe material price is moderate, reliable standard mutual melting hot-melt connection form, the diameter of the pipe fitting part is larger than the inner diameter of the same specification of pipe. Compared with other products, the construction is convenient and fast, and the connection form belongs to the current stage. Due to the mechanical connection without local shrinkage in the system Therefore, the system fluid resistance is relatively small.

　　Large blind flange long-lasting pressure resistance function, only from the design stress, large blind flange pressure resistance function is good. However, due to various factors, the actual wall thickness of floor heating pipe is usually only 2mm. Under this wall thickness, all kinds of pipes can meet the requirements of floor heating, so the pressure resistance advantage of large blind flange is easy to emerge;

　　Environmental protection of large blind flange: PE-RT can be recycled without environmental pollution. But PEX can not be recycled, which will lead to secondary pollution.