Electric Resistance Welding (ERW) Tube Mills and Seamless Tube Mills are two different manufacturing processes used to produce tubes with distinct characteristics. While it might seem counterintuitive that ERW tube mills are sometimes more expensive than seamless tube mills, several factors contribute to this cost difference:
1. Complexity of Manufacturing Process: The manufacturing process for ERW tubes involves several stages, including forming, welding, and sometimes additional processes such as sizing and straightening. These multiple steps and the need for precise control during welding increase the complexity of the ERW tube manufacturing process, leading to higher equipment and maintenance costs.
2. Welding Equipment and Quality Control: The welding process in ERW tube manufacturing requires advanced equipment to generate the electric current needed for the resistance welding. This equipment needs to be maintained and calibrated regularly to ensure consistent and high-quality welds. Quality control measures to detect any welding defects, such as cracks or lack of fusion, also add to the overall cost.
3. Energy Consumption: The ERW process requires significant energy to generate the electric current for welding. This energy consumption contributes to operational costs and can impact the overall cost of producing ERW tubes.
4. Waste and Scrap: The ERW process can lead to a higher rate of waste and scrap compared to the seamless process. Imperfections or defects in the welded seam may lead to rejected tubes, increasing the overall production cost.
It’s important to note that while ERW tubes might be more expensive to produce compared to seamless tubes, their cost-effectiveness in certain applications should also be considered. ERW tubes can offer advantages such as high dimensional accuracy, smooth surface finish, and suitability for various sizes and wall thicknesses. The decision to use either ERW or seamless tubes depends on the specific requirements of the project, including factors like cost, performance, and intended application.