Caliber flange flat welding flange and butt weld ends are so common flange threaded flange is not in the real production and sales of large diameter, or much more flat welding products accounted for the proportion of flat welding of large diameter flange and butt welding of large diameter flange structure and use of the range is different, can show the characteristics and advantages of also will be different, so when use should be used according to different range, to ensure the flange play an important role of large-diameter flat welding flange with poor rigidity, suitable for pressure p 4 mpa occasions;Butt welding flange, also known as high neck flange, rigid, suitable for high pressure temperature occasions.
There are three types of flange sealing surface: plane sealing surface, suitable for non-toxic occasions of medium with low pressure;Concave and convex sealing surface, suitable for slightly high pressure occasions;Mortise sealing surface, suitable for the occasion of inflammable and explosive toxic medium and high pressure, large diameter flange collocation with fasteners used in application, the following said the application of the two characteristics: first is the mechanical properties of large diameter flange style should be along the rolling direction after heat treatment on the blank of stealing, so cut off position is: if the blank is not more than 40 mm diameter, then there should be at the center of sampling;If the diameter of the blank is greater than 40mm, then the equilong double-head stud and full-thread stud sampled at the center at a quarter of the diameter shall be tested in batches and the nuts shall be tested in batches for hardness;The raw materials used for special fasteners shall have the material qualification certificate of the manufacturer.

Flange is fasteners for fastening and widely application of mechanical parts are widely used all kinds of mechanical equipment vehicles instrumentation ship structure of railway bridge construction tools and supplies such as above, you can see all kinds of fasteners, it is the feature of variety specification is various, performance different purposes, and standardized series of generalizing large diameter flange kind of degree is also very special fasteners, should according to the number of sampling inspection after heat treatment, inspection results shall comply with the relevant provisions of, and shall ensure that the mechanical properties of the product is not lower than the performance of the sampling conditionAll studs used for large-diameter flanges with nominal pressure PN no less than 10.0MPa shall be inspected by magnetic particle according to the non-destructive inspection of JB 4730-1994 pressure vessels one by one. After the inspection, there will be no problem with the product, and it shall meet the requirements of large-diameter flanges of secondary forgings