1. Different weld types:
Slip On Flanges: fillet weld is used for welding between flange pipe and flange.
Weld Neck Flanges: the welding seam between flange and pipe is circumferential weld.
2. Different materials:
Slip On Flanges is machined from ordinary steel plate with thickness meeting the requirements.
Weld Neck Flanges is mostly machined from forged steel.
3. Different nominal pressures:
Nominal pressure of Slip On Flanges: 0.6 — 4.0MPa
Nominal pressure of Weld Neck Flanges : 1-25MPa
4.Different structures
Slip On Flanges: refers to the flange that extends steel pipes, pipe fittings, etc. into the flange and connects with equipment or pipes through fillet welds.
Weld Neck Flanges: a flange with neck and a pipe transition, which is connected with the pipe by butt welding.
5.Scope of application:
Slip On Flanges : it is applicable to the connection of steel pipes with nominal pressure not exceeding 2.5MPa. The sealing surface of the flange can be made into three types: smooth type, concave convex type and mortise type. The application of smooth flange is the largest It is mainly used in the case of moderate medium conditions, such as low pressure non purified compressed air and low pressure circulating water.
Weld Neck Flanges : it is used for butt welding of flanges and pipes. Its structure is reasonable, its strength and stiffness are large, it can withstand high temperature and high pressure, repeated bending and temperature fluctuations, and its sealing is reliable. The neck butt welding flange with nominal pressure of 1.0~16.0MPa adopts concave convex sealing surface.
The flat welding flange can only be connected with the pipe and cannot be directly connected with the butt welding pipe; Butt-welding flanges can generally be directly connected to all butt-welding pipe fittings (including elbows, tees, pipes with different diameters, etc.), and of course, pipes.
The rigidity of the neck butt welding flange is greater than that of the neck flat welding flange, and the butt welding strength is higher than that of the flat welding flange, so it is not easy to leak.
The neck flat welding flange and neck butt welding flange cannot be replaced at will. In terms of manufacturing, the neck flat welding flange (SO flange) has large internal warpage, small weight and low cost. In addition, the neck butt-welding flange with a nominal diameter greater than 250 mm (WN is the abbreviation of WELDINGCHECK) needs to be tested, so the cost is relatively low.
Flat welding with neck is widely used in imported petroleum equipment, similar to the American standard S0. Butt-welding flanges are used for highly hazardous media.
Butt-welding flange refers to the pipe diameter and wall thickness of the connecting end, which is the same as the pipe to be welded, just as two pipes are welded.
The flat welding flange is a concave platform, its inner hole is slightly larger than the outer diameter of the pipe, and the pipe is inserted into the internal welding
Flat welding and butt welding refer to the welding methods of flange and pipe connection. When welding the flat welding flange, only one side welding is required, and there is no need to weld the pipe and flange connection. The welding and installation of the welding flange needs to be welded on both sides of the flange. Therefore, the flat welding flange is generally used for low pressure and medium pressure pipes, and the butt welding flange is used for medium and high pressure pipe connection. The butt welding flange is generally at least PN2. 5 MPa, use butt welding to reduce stress concentration. Generally, butt welding flange is also called high neck flange with neck flange. Therefore, the installation cost, labor cost and auxiliary material cost of welding flange are high, because there is only one process for welding flange.
Post time: Sep-27-2022
