The weld form is different: the weld seam cannot be radiographic inspection, and the weld seam can be welded. The welded weld seam with slip on flange pipe and flange is a fillet weld, and the welding weld seam with neck weld neck flange and pipe is ring weld; the flat weld is a two-fillet weld, Butt-weld. The difference between slip on flange with neck slip on and without neck is that the slip on flange is more than one spot in the pipeline welding area without slip on flange. Without slip on flange is the flat flange, no flange of the convex table is also the fillet weld. The weld seam with neck weld neck flange and nozzle connection belongs to Type B seam, the weld seam with slip on flange and the connecting pipe is C type seam, the nondestructive testing is different after welding.The material is different: with the slip on flange material for the thickness of ordinary steel plate machined, and with neck weld neck flange material for forging steel machine processing.
The nominal pressure is different: with the slip on flange called the pressure is: 0.6—4.0MPa, and with the neck weld neck flange pressure is: 1–25mpa grade, obviously, with slip on flange of the adaptation of lower pressure level.
The connection way is different: with the slip on flange and the weld neck flange In the structure the biggest difference is that the takeover and the flange connection way difference, with the slip on flange is usually taken over and flange angle connection, and the neck weld neck flange is flange and take over the joint slip on flange can only be connected with the pipe, but not directly with the welding pipe fittings; weld neck flanges can be directly connected with all welding fittings (including elbow, tee, reducer, etc.), including piping.
The stiffness of the flange with neck butt welding is greater than that of the flange with the neck, and the than welding strength is high and it is not easy to leak.
With slip on flange and weld neck flange can not be replaced casually, in terms of manufacturing angle with slip on flange (so is slip on abbreviation) inside the large, means that the weight is small, the cost is low, in addition the nominal diameter is greater than 250mm with neck weld neck flange (WN is welding neck abbreviation) to detect, so the flange does not need to detect, so the cost is relatively low some.
