1. The damage of the specimen generally occurs at the experimental steel pipe, in which the high neck flange weld and the middle section of the experimental steel pipe are simply damaged.Bolts of M20 and M30 can meet the requirements in the experiment without damage.
 

2. Under the planned load, all parts of high-neck flange specimen are in the elastic stage.The yield capacity of the experimental steel pipe and flange neck can reach more than 1.4 times of the planned load.

3. For typical high-neck flanges, the effects of flange diameter, flange plate thickness, flange neck height, steel pipe diameter, flange neck diameter and flange bolt orientation on the stress of flange neck and flange plate were studied by finite element parameter analysis.It is suggested that the thickness of the flange plate and the height of the flange neck can be reduced by 1000. At the moment, the bearing capacity of the flange plate and flange neck can still reach 1.4 times of the planned load.

4. The high-neck flange has a large bearing capacity in the experimental process, and the structure has a significant warning before the damage, which meets the strength requirements under the planned load and can be widely used in engineering.