Connection mode of high pressure pipeline is the main thread, flange connections and welded connections two. The interface processing shall be made in cold machining, achieve the interface size specification. In general, the lathe bed and cone tube processing lathe, welding method can be used for manual processing interface.
High pressure stainless steel pipe fittings’ pipe end of thread on the machining accuracy requirements are higher, meet the requirement of precision and the surface is bright and clean degree to reach more than 75], the tube end sealing cone (20 degrees plus or minus 30 DEG) surface finish to more than 76%], does not allow any scratch, scratch, cavities and other defects. The sealing surface with the center line and the concentric lens gasket sealing line
(often called the DK line) to be accurate. Pipe end processing should be carried out to check the thread in the thread angle, tooth shape and so on should meet the requirements. There is no crack or burr on the surface of the thread. The teeth are not complete and minor mechanical damage should not be more than 1/3 circle thread. To reduce the height of thread should not exceed the nominal height of 1/5. Finally by the use of magnetic particle inspection pipe end, not allowed to crack, the cleaning after coated with lubricating oil, it is best to use cover protection, can also be equipped with flanges protection.
The processing for the straight pipe end, and cold-formed stainless steel pipe fittings, stainless steel pipe or central heat bend without heat treatment of high pressure pipe and the elbow, the elbow can before the pipe thread lathe. Stainless steel pipe of hot bending to do the overall heat treatment, and the closed pipe (including cold and hot bending) and pipe end processing must be performed after forming, it must be in town bed processing stainless steel pipe end, hit the bed file of pipe end thread is difficult, but doing so can ensure installation quality of the high pressure pipeline.
Source: Zhejiang Yaang Pipe Industry Co., Limited (www.yaang.com)