What is the difference between neck flat welding flange pipe welding and butt welding flange pipe welding?
Welding methods are different:
The electric welding method of the neck flat welding flange pipe and the flange is fillet welding, while the electric welding method of the butt welding flange and the pipe is a girth welding;
The materials are different:
The neck flat welding flange material is machined from a general thick steel plate with a thickness that meets the regulations, while the butt welding flange material is mostly machined from forged steel parts;
The nominal diameter is different:
The nominal diameter of the flat welding flange is: 0.6—4.0MPa, while the nominal diameter of the butt welding flange is: 1–25MPa.
Other differences:
The weld between the butt weld flange and the butt joint is a Class B seam, and the weld between the neck flat weld flange and the butt joint is a Class C joint.
The post-weld non-destructive testing technology is different.
The flat welding flange and the butt welding flange cannot be replaced casually.
From a manufacturing perspective, the inner diameter of the necked flat welding flange is large, which means the weight is small and the cost is low.
In addition, the butt welding flange with an outer diameter exceeding 250mm must be inspected. , SO’s flange does not need to be inspected, so the cost is low.
The interface methods are different:
The biggest difference between the structural types of neck flat welding flanges and butt welding flanges depends on the different connection methods between the joint and the flange.
Neck flat welding flanges generally have joints and flange angle joints, while butt welding flanges It is the connection between the flange and the connector.
Difference 1:
Flat welding flanges generally can only be connected to pipelines, but cannot be connected to butt welding pipe fittings at the same time; butt welding flanges can generally be directly connected to all butt welding pipe fittings, including pipelines.
Difference 2:
The stiffness of the butt welding flange is greater than that of the flat welding flange. The butt welding flange is stronger than the vertical welding and is less likely to leak.
Difference 3:
The neck flat welding flange and the butt welding flange cannot be replaced casually. From a manufacturing perspective, the neck flat welding flange has a large inner diameter, which means a small weight and low cost.
In addition, the butt welding flange with an outer diameter of more than 250mm To be inspected, SO’s flange does not need to be inspected, so the cost is relatively low.
Difference 4:
Vertical welding with neck is commonly used in imported crude oil equipment. It is similar to the American standard bottom S0. Butt welding flange is used for relatively highly harmful substances.