What Is the Difference Between The Neck Butt Welded Flange and The Neck Flat Welded Flange

1.The weld method is different: flat welding weld can not X-ray detection, and butt welding weld can. The welding weld method between pipe and flange with neck flat welding flange is fillet weld, while the welding weld method between flange and pipe with neck butt welding is girth weld. Flat welding is two fillet girth welds and butt welding is one butt girth weld. The difference between plain welded flange with neck and plain welded flange without neck is that plain welded flange with neck is more than that without neck plain welded flange in the welding position of the pipeline. Plain welded flange without neck is also a flat flange, and the boss without flange is also a flat fillet weld. The welds connecting neck butt welding flange with receiving belong to Class B joints, while the welds connecting neck flat welding flange with receiving belong to Class C joints, and the non-destructive testing after welding is different.

2.Nominal pressure is different: with neck flat welding flange nominal pressure is: 0.6-- 4.0MPa, and with neck butt welding flange nominal pressure is: 1--25MPa grade, obviously, with neck flat welding flange to adapt to the pressure grade is lower.

3.The connection method is different: with neck flat welding flange and neck butt welding flange in the structure of the great difference is the difference between the receiving and the flange connection method, with neck flat welding flange is generally received and flange Angle, and with neck butt welding flange is flange and receive butt.

With neck flat welding flange general can only connect with the pipe, but not directly with the butt welding pipe fitting; Butt welded flange can generally be directly connected with all butt welded pipe fittings (including elbows, tees, reducing pipes, etc.), of course, including pipes.

The stiffness of butt welding flange with neck is larger than that of flat welding flange with neck, and the strength of butt welding is higher than that of flat welding, which is not easy to leak.

Neck flat welding flange and neck butt welding flange can not be replaced casually, in terms of the production point of view with neck flat welding flange large internal longitude, meaning small weight, low cost, other nominal diameter is larger than 250mm with neck butt welding flange to test, SO flange does not need to be tested. So the cost is relatively low.

With neck flat welding is introduced on the petroleum device is used more, similar to the American standard S0, with neck butt welding flange for highly damaging media.