With more than 90 years' experience in steel pipe manufacture and a commitment to pushing the boundaries of pipe-thickness practicality with its patented Impander technology, Eisenbau-Krämer can rightfully consider itself a visionary in the field.
Eisenbau-Krämer (EBK), based in Dahlbruch, Germany, is able to draw on many years of experience within the steel pipe manufacturing industry, as the company's mill was founded in 1923. Since the 1970s, the business has focused its activities on developing large-diameter, thick-wall steel pipe solutions for oil and gas companies. As the offshore industry expands into harsher environments and pipes are installed in deeper water, Eisenbau-Krämer remains at the forefront of innovation within the market and continues to meet the most stringent requirements of the industry.
A clear commitment to product quality, excellent customer service and R&D provides the foundation of the company's activities. EBK was one of the first mills in the world to produce pipes with very heavy wall thickness. Previously, the industry was limited to a maximum wall thickness in the range of 35-40mm for pipes in 12.0m lengths without circumferential welds. EBK removed this limit, enabling pipe lengths of up to 13.4m in length with very heavy walls of 70-80mm to be produced. This progress led to an involvement not only in offshore construction projects around the globe but also the offshore line-pipe sector, which remains an important part of
the business to date.
Being at the cutting edge of technological R&D has always been EBK's remit. Currently, the mill has one of the heaviest pipe-wall manufacturing capabilities in the world and has now expanded into developing more technically sophisticated products. Ten years ago, API 5L X52 steel was the standard within the offshore line-pipe market. Today, EBK is commercially supplying products up to X100, and is developing the X120 and X140 ranges. Currently, there are only a few mills in the world that are supplying X80 pipes for sour service.
EBK has continued to place emphasis on R&D to advance steel pipe production technology at its three production facilities located in Germany. Involvement with steel suitable for low-temperature application started in the 1970s with carbon steel line pipe for the offshore oil and gas industry. Further developments resulted in 3.5%-nickel steel pipes becoming available, generating interest from the market to further increase the nickel content in pipes to a level that would be suitable for application in the transmission of liquefied natural gas (LNG).
On this basis, in 2005, EBK embarked upon an extensive R&D programme initially focused on overcoming the difficulties associated with the production of 9%-nickel steel pipes. This was later extended to include a similar R&D programme for 36%-nickel materials. EBK has now produced 9 and 36%-nickel pipes, including tubes for subsea pipe-in-pipe solutions, and in this is unique, being the only steel mill in the world to have commercially supplied 9 and 36% nickel tubular products.
Additionally, the company has developed revolutionary welding processes and unique filler metals for these nickel pipes. These new welding methods are able to provide overmatching mechanical values for longitudinal and circumferential welds, and include site-friendly techniques to enable this technology to be used in field welding without compromising weld integrity. These developments are key points and have enabled engineers to design practicable LNG pipe-in-pipe solutions for the first time.
In order to meet the new requirements of the pipe market, the traditional pipe-calibration technique for large-diameter steel pipes had to be modified in order to allow limited pipe tolerances to be produced.
The main principle of the Impander technique is to plasticise the pipe body by regularly compressing the material until the pipe circumference becomes ideal. In contrast to standard pipe calibration, the Impander technique produces a constant circumferential pressure, plasticising the base material and thus making the pipe the optimum circular shape required.
Furthermore, residual stress on the pipe is reduced by the Impander technique. In order to realise this technique, a new machine was developed, patented and named Impander. The four-tool Impander installed at EBK's site in Dahlbruch is designed for the following application:
Longitudinal welded pipes produced applying the Impander technique (Impanded pipe) have tighter tolerances over the whole pipe length even after cutting, reduced pipe stress and higher pipe-collapse resistance than traditionally welded pipes.
Consequently, as an advanced European producer of high-quality SAW pipes, EBK stands at the forefront of technology, providing users around the world with products they can rely on under the most demanding conditions.