Flat welded flange and butt welded flange are two common types of flanges, what is the difference between the two? In fact, there are still significant differences between flat welded flange and butt welded flange in many aspects, the following is the specific difference between the two:
- Material
Flat welded flange: The material is usually machined from ordinary steel plate whose thickness meets the requirements.
Butt welded flange: The material is mostly machined from forged steel parts, which has higher strength and toughness.
- Nominal pressure
Flat welding flange: nominal pressure range is generally 0.6~4.0MPa, suitable for medium and low pressure grade pipeline system.
Butt welded flange: nominal pressure range is usually 1~25MPa, suitable for medium and high pressure grade pipeline system.
3, weld form
Flat welded flange: The weld form is a fillet weld, usually consisting of two fillet girth welds. The welding seam with neck flat welding flange and nozzle connection belong to class C seam, and the non-destructive testing after welding has special requirements.
Butt welded flange: The weld form is a girth weld, usually a butt girth weld. The welding seam with neck butt welding flange and nozzle connection belong to class B seam, and there are also specific requirements for non-destructive testing after welding.
- Application occasions
Flat welded flange: Because of its simple structure, material province and low price, it is widely used in the connection of medium and low pressure vessels and pipelines, but it is not suitable for high temperature and high pressure or highly hazardous media such as flammable and explosive.
Butt welding flange: Because it is not easy to deform, good sealing, widely used, and has the corresponding rigidity and elasticity requirements and reasonable butt welding thinning transition, it is suitable for pipelines with large fluctuations in pressure or temperature or pipelines with high temperature, high pressure and low temperature, and pipelines with expensive, flammable and explosive media.
