2. Size: 2" (DN50)
3. Standard: AS 2129
4. Type: Table E
Slip-on bossed flanges are designed to slip over the pipe and are machined with the inside diameter of the pipe flange slightly larger than the outside diameter of the pipe.
These allow the flange to slide over the pipe and are joined to the pipe with a fillet weld at the top and the bottom of the flange.
A bossed type has a reinforcing disc around the outside of the pipe which helps support the pipe making for a stronger joint.
In Australia the BS and AS flange standards are essentially the same but have been metricated. Consequently metric sizes are stated as ‘DN’ (Nominal Diameter) in mm. Equivalent imperial sizing is rounded to the nearest multiple of 25mm (for 2” and over) as below. However the actual dimensions and bore sizes have not changed. ‘NB’ (Nominal Bore) is also sometimes used when referring to valve sizes.
AS2129 originates from BS10 and has been metricated. In some cases slightly larger bolt holes provide better clearance as metric bolts are specified in lieu of UNC bolts used by BS10. AS4087 is an update of AS2129, however AS2129 is still widely used so it has not been deleted as a standard, however, it now only covers AS table D, E to H.
China Bossed Flange Manufacturer Yaang supplies AS 2129 T/E 316L Bossed Flange Flat Face, 2 Inch.