What Is The Difference between ERW And EFW?

ERW (Electric Resistance Welded) and EFW (Electric Fusion Welded) are two different welding methods used for producing welded tubes or pipes. The main differences between the two methods are as follows:

1. Welding Process: ERW welding involves the use of a high-frequency electrical current to generate heat and fuse the edges of the steel strip or plate together. EFW welding, on the other hand, uses a combination of electric arc and welding consumables to create a molten weld pool, which solidifies into a joint.

2. Application: ERW welding is commonly used for the production of pipes and tubes in a wide range of industries, including oil and gas, construction, and agriculture. EFW welding, on the other hand, is typically used for producing larger and heavier wall thickness pipes, mainly in high-temperature and corrosive environments, such as in petrochemical industries.

3. Strength and Integrity: ERW welding produces a stronger and more durable weld due to the continuous fusion of the edges along the length of the tube. The EFW welding process may result in a slight variation in the strength and integrity of the weld due to the intermittent welding arcs.

4. Seam Appearance: ERW welding creates a visible seam along the length of the tube or pipe, which may require additional processing or finishing. EFW welding, on the other hand, produces a seamless appearance without any visible external seam.

5. Production Speed and Cost: ERW welding is a faster and more cost-effective process compared to EFW welding. The continuous nature of ERW welding allows for higher production speeds, making it suitable for mass production. EFW welding is a slower process and requires more complex equipment, making it generally more expensive.

It is important to consider the specific requirements of the application and the intended use of the welded tubes or pipes when selecting between ERW and EFW welding methods.