W N(weld neck) flange is circumference welded into the pipeline at its neck which means that the integrity of the butt weld area can be easily examined by radiography. The bores of both pipe and flange match, which reduces turbulence and erosion inside the pipeline. The weld neck is therefore favored in critical applications. weld neck flange (W N flange) Standard: ANSI B 16.5 pressure size 150 LB 1/2"-24" 300 LB 1/2"-24" 600 LB 1/2"-24" 900 LB 1/2"-24" 1500 LB 1/2"-24" 2500 LB 1/2"-12"

Slip-on flange(SO flange) is slipped over the pipe and then fillet welded. Due to it’s easy welding and economic spending features, slip-on flanges are usually widely used in the low and medium pressure pipeline system.