Butt welding flange is a kind of pipe fitting, it refers to the flange with neck and a round pipe transition and butt welding connection with the pipe.Welding flange is not easy to deformation, good sealing, widely used, there are corresponding rigid and elastic requirements and reasonable welding thin transition, welding from the joint surface distance, the joint surface from welding temperature deformation
Welding neck flange is not easy to deformation, good sealing, wide application, have corresponding rigid and elastic demand and reasonable butt thinning transition, joint good distance away from the joint face the faying surface from welding deformation temperature, it take more complex syndromes beep form structure, suitable for pressure or temperature fluctuations of pipeline or high temperature, high pressure and low temperature pipes, commonly used in PN is greater than 2.5 MPa pipe and valve connection;Also used to transport expensive, flammable, explosive medium pipeline.
Product Name:Weld Neck Flange
1. The grade of butt welding flange and its technical requirements shall meet the corresponding requirements of jb4726-4728.1, the nominal pressure PN 0.25 MP 1.0 MPa carbon steel and austenitic stainless steel forgings allowed the use of level Ⅰ forgings.2, in addition to the following provisions, nominal pressure of PN 1.6 MPa to 6.3 MPa forgings shall conform to Ⅱ level or above level Ⅱ forgings levels.3, conform to one of the following should accord with the requirement of Ⅲ and forgings: (1) nominal pressure PN acuity 10.0 MPa flange forging;(2) chromium molybdenum steel forging with nominal pressure PN>4.0MPa;(3) forgings of ferritic steel with nominal pressure PN> 1.6mpa and operating temperature ≤-20 ℃.
Two, welding flange is generally made of forging or forging rolling process.When using steel plate or section steel manufacturing, must meet the following requirements: 1. Welding flange should be ultrasonic testing, no stratification defect; 2.2, should be along the steel rolling direction cut into strips, through the bending butt welding into a ring, and the surface of the steel ring cylinder.No steel plate shall be machined directly into butt welding flanges with neck;3. Full penetration weld shall be adopted for the butt weld of the ring;4. The butt weld of the ring shall be subjected to post-welding heat treatment and be subject to 100% X-ray or ultrasonic inspection, and the X-ray inspection shall meet the requirements of grade II of JB4730, and the ultrasonic inspection shall meet the requirements of grade I of JB4730.
3. The lateral slope of butt welding flange shall not be greater than 70°.Welding flange in the production and welding strict control of technical parameters, to ensure that the production and use of the full play of the role and value.