Pipe fitting reducer under internal pressure

　　The bending moment caused by the area pressure difference between the large and small ends of the pipe fitting reducer under the action of internal pressure causes the phenomenon of the relative opening of the large end and the relative contraction of the small end. Under the action of internal pressure, the circumferential stress of eccentric pipe with reducer, the inner surface of the big end of the eccentric side and the outer surface of the middle part of the eccentric side are the greatest. The above theoretical results are verified by finite element numerical analysis and experimental verification. The experimental results also show that the bending radius and the cross-section radius of the annular shell increase with the internal pressure, while the thickness of the pipe changes little.

　　Pipe fitting reducer expanding is formed by adopting a tube blank smaller than the pipe fitting reducer, and expanding along the inner Carbon Steel Concentric Pipe Fitting Reducer blank with an internal stamping die. The expanding process mainly solves the problem that it is difficult for the tube with lpipe fitting reducer to be formed by shrinkage. Sometimes the expanding and shrinkage methods are combined according to the forming needs of materials and products.