Flat welding flange

Flat welding flanges include plate type flat welding flanges and neck type flat welding flanges.

Overview of Flat welding flanges

• Plate type flat welding flange (PL)
  Flat welding flanges are suitable for connecting steel pipes with a nominal pressure not exceeding 2.5MPa. The sealing surface of flat welding flanges can be made into three types: smooth, concave convex, and tenon groove. Smooth flat welding flanges are the most widely used. It is often used in situations where the medium conditions are relatively mild, such as low-pressure non purified compressed air and low-pressure circulating water.

• Flat welding flange with neck (SO)

  The neck height of the flat welded flange with a neck is relatively low, which improves the stiffness and load-bearing capacity of the flange. Compared with butt welded flanges, welding requires a large amount of work and high electrode consumption, which cannot withstand high temperature and pressure, repeated bending, and temperature fluctuations. However, on-site installation is more convenient, and the process of welding seam rubbing can be omitted, making it more popular.

Features of Flat welding flanges

Flat welded flanges not only save space and reduce weight, but more importantly, ensure that the joint area does not leak and have good sealing performance. The reason why the size of the compact flange is reduced is because it reduces the diameter of the sealing element, which will reduce the cross-section of the sealing surface. Secondly, the flange gasket has been replaced by the sealing ring to ensure that the sealing face matches the sealing surface. In this way, only a small amount of pressure is required to compress the sealing surface. As the required pressure decreases, the size and quantity of bolts can be correspondingly reduced, so a new product with small volume and light weight (70% to 80% lighter than traditional flanges) was ultimately designed. Therefore, the flat welded flange is a relatively high-quality flange product that reduces quality and space, and plays an important role in industrial applications.

Techspecs

• Outer diameter of flange: 75mm-2190mm  

• Bolt hole center circle diameter: 50mm -2130mm  

• Bolt hole diameter: 11mm-30mm  

• Number of bolt holes: 4-48  

• Thread: M10-M27  

• Flange thickness: 12mm-58mm  

• Pipe outer diameter: A (17 2-2032MM) B (14-2020MM)  

• Flange inner diameter: A (18-2036MM) B (15-2024MM)  

• Theoretical weight of flange: 0.36kg --234.6kg (DN1800)  

• Flange pressure: 0.25MPa-4.0MPA  

Applications of Flat welding flanges

• Used for transporting expensive, flammable, explosive media or media containing high concentrations of hydrogen sulfide, carbon dioxide, water vapor, and other harmful gases.

• Long distance pipelines for flammable gases or liquefied petroleum gas that are not suitable for threaded connections in flammable and explosive locations can use directly buried prefabricated insulation pipes.

• Suitable for galvanized lined plastic spiral corrugated compensators for water supply in high-rise buildings and indoor hot water pipeline systems.