The rotary flange is a special type of necked flange whose outer ring allows the inner ring to rotate 360 ​​degrees for quick alignment of bolt holes with a standard flange. This feature makes it ideal for offshore/subsea pipeline operations and allows divers to adjust bolt holes faster and easier.

Swivel flange is a kind of special weld neck flange whose outer ring allows 360° rotational of the inner ring for rapid alignment of bolt holes with the standard flange. the feature makes it ideal for offshore/subsea pipeline operations, which allows divers to adjust bolt holes more quickly and conveniently.
In addition to pipeline systems, swivel flanges are used in other industrial equipment like heat exchangers, pumps, and tanks. Lap joint flanges, on the other hand, are commonly used in applications where the piping system needs to be easily disassembled for maintenance or inspection.
The most common flange types are: Welding Neck Flange. Slip-on Flange. Socket Weld Flange.
The bar of gold has been hammered into 'flanges' and then twisted anti-clockwise to create a 'flange twisted' form. The terminals of the bar are plain and circular in cross-section and slightly expand towards a convex end. These are hooked around each other, completing the circle of the torc.