Production process of forged flange and cast flange

Flange is a kind of connection sealing parts. If there are quality problems in the production process, there will be leakage, resulting in economic losses, environmental damage and even safety accidents. So the welding and production of flange is very important.

At present, the flange production process mainly includes forging and casting. Let’s learn about these two main production processes and see what the difference between them.

Forged flange

Forged flange is through countless times of hammering by forging machine to make the internal structure of steel become closer, so the mechanical properties will be better and the strength will be higher. The forged flange is mainly suitable for those pipes with higher pressure.

First of all, the cylindrical billet is cut according to a certain size. After being heated to a certain temperature, it becomes thermoplastic, and placed on the cold heading machine to continuously hammer the billet. Then, the internal of the billet is more compact and the mechanical properties are better than the original billet.

The round hole above the flange should be punched out on the billet by the stamping machine. The formed blank flange should be put into the electric furnace for heat treatment to increase the strength of the flange. Finally, the flange blank should be cut and polished to become a usable flange.

Weld neck flange WN flange A182 Gr F321 RTJ ASME B16.5

Weld neck flange WN flange A182 Gr F321 RTJ ASME B16.5

Cast flange

Cast flange has the characteristics of low cost and high efficiency, which can produce the flange with complex shape. Cast flange is mainly suitable for those pipes with low pressure.

Cast flange is also a commonly used manufacturing process, which melts the metal into liquid steel, pour the molten steel into the metal mold which is preheated and kept constant temperature to form the shape of flange. After the casting is naturally cooled for a period of time, it is cooled and demoulded rapidly with water, which can also increase the strength of the flange. Finally, it can be used after polishing and antirust treatment.

Although flange is a small part in the whole product, pipeline or machinery, the role of flange is very important. In the future, with the development of flange material and technology, it can ensure that the whole joint connection process is more precise and firm, and ensure the safety and reliability when people use it.