Flange WN50-25 what do you mean?
Butt welding flange DN50 caliber pressure grade 2.5MPa
Butt welding neck flange, DN50 25, this depends on what is behind the unit, if it is 25MPA, the pressure of 250 kg, 25bar, 25 kilograms of pressure, because the welded flange DN50 specifications, including the two kinds of pressure are possible.
WN indicates that the weld flange 50 is DN, 25 is the pressure 25 kg, and the pressure may be 250 kg. The pressure depends on what standard he performs
