TPT May 2010

T echnology U pdate

New trends for ERW pipe mills

makes a positive. The problem is that the mill working condition is not stable even in a critical condition. Every tiny change of the mill may break the balance. That is why some adjusters can spend longer than needed making constant changes to the mill. The busier the adjuster, the lower the product quality and quantity and the lower the profit. In the pipe industry the adjustment time for producing the end products is important to the end user. Some pipe mill manufacturers may fail to notice this, when they are focusing on the methods of changing rolls. The adjustment problems are exposed, after the changeover period is shortened and the workload is reduced by the improvement of mill construction. These problems can be classified as adjustment duration, adjustment workload, rawmaterials and power consumption. Those who have the experience of producing ERW pipes know how important an adjuster is. Also, to train a qualified pipe mill adjuster can take a very long time. Since high quality, speed mills are popular in the market, the company said the ERW pipe mill with DNSA technology could become important for future ERW pipe mills due to its efficient performance. Dalian Field – China Fax: +86 41183 192716

DALIAN Field Company is an ERW pipe mill manufacturer that prides itself on developing quick-change technology. The company has many approved patents in this area such as cage forming for square pipe forming machines, which operate without changing rollers when changing product size. The cage forming square and round pipe forming machine is the first machine to combine cage and directly square and rectangular forming together, less roller quantities, shorter changeover time and a higher degree of automation. Along with the further development of pipe mill technology, Dalian Field said it has conducted a number of studies on simplifying the operation of a pipe mill. ‘Digital – no load – setting – adjustment’ (DNSA) technology was brought in following the research. Firstly, all setting points are displayed in a numerical way, as numeralisation is the foundation of DNSA technology and leads to many important improvements. For example, it is used when building a mathematic model to program the adjustment of the mill. Even an inexperienced worker can adjust the mill to high precision and produce qualified pipes with little or no waste after reading the manual or 10 minutes simple training.

The mill with DNSA technology not only has less waste, a shorter time to make adjustments and low dependence on operator’s experience, but also has a trouble-free operation. From a practical point of view, the mill has good tolerance with the raw material and strip joint quality, because the rollers are in pinpoint control. A normal pipe mill is also able to produce qualified products, but often depends on the operator’s experience. The adjustment is done wth the eye of an experienced worker. They cannot ensure each roller is in exactly the correct position. They can only adjust the mill to produce qualified pipes. For the DNSA pipe mill, every roller is in the correct position, so the mill’s working condition is stable, and the mill has a strong ability to resist outside interference. For the normal pipe mill, every roller may not be in the correct position and the adjuster does not know which roller is in the wrong position and how much the offset is. They can only can adjust rollers by observing the actual running strip. Sometimes correct rolls are adjusted and wrong rolls are not adjusted, then all the rollers are adjusted on an offset position. It also can produce qualified pipes, just like the mathematical law – double negatives

Email: field@asiafield.com Website: www.asiafield.com

The Dalian Field ERW pipe mill

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M ay 2010

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