The EN 1092-1 Type 01 flange is also known as “plate flange for welding”. Usually, it is also called “steel ring flange” or “S/O plate flange”. It is a loose type flange which is very similar to slip on flange but without hub. The Type 01 plate flange can slip onto the pipe prior to welding. Two fillet welds, one internal and one external, shall be applied to join the pipe and the flange. They can be furnished with flat face (FF) or raised face (RF) depending on buyer’s requirement. According to EN 1092-1, Type 01 plate flanges are available in 8 pressure ratings: PN 2.5, PN 6, PN 10, PN 16, PN 25, PN40, PN 63 and PN 100. All dimensions are in mm unit.