TPT July 2015

Straightening

New solution for mechanical bonding of CRA lined pipes

the CRA material to carbon steel: metallurgical bond (CRA clad pipes) and mechanical bond (CRA lined pipes). The metallurgical bond between two different metals (bonding of plates) is achieved by hot rolling, co-extrusion, weld overlay or explosive bonding. A disadvantage is the limited number of suppliers due to the demanding and complex manufacturing process of metallurgically bonding the plates, which creates high costs. Mechanical bonding between the backing steel pipe and the CRA pipe by use of spring back variation can be performed by means of hydroforming or by a full length pipe expander. There is growing demand for CRA lined pipe due to the fact that corrosive conditions are expected to increase as produced fluids contain higher water cuts and greater concentrations of H 2 S and CO 2 . In addition, these increasingly corrosive products need to be transported over longer distances, with higher pressures, and in an environmentally friendly way. Fontijne Grotnes has found a solution to bond the backing steel pipe and the CRA pipe with the company’s full length pipe expander, for which a patent is pending. The company has more than 40 years’ experience in designing and manufacturing full length pipe expanders for the LSAW pipe industry. The expander head, actuated by the main cylinder and horn and drawbar expands the pipe sections from the inside. This ensures a constant production process according to API 5L through calibration of the pipe over the full length in roundness and diameter; straightening of the pipe; testing of the pipe weld seam; stress relief of material in way of the weld zone; and improvement of mechanical properties by exceeding the material yield strength. For bonding CRA lined pipes by means of a full length pipe expander, the inner and outer pipe are telescopic aligned and subsequently positioned on the infeed and outfeed loading cart. The pipe is fed incrementally with the use of the loading cart over the expander head. Fontijne Grotnes Group – Netherlands Website: www.fontijnegrotnes.com

for sour gas and oil, water reinjection systems, saltwater pipelines, and process pipes in the chemical industry. CRA lined pipes are mainly used as flow- lines, riser pipelines, interfield pipelines and water injection pipelines. There are two methods of bonding

CRA lined pipes or CRA clad pipes are corrosion-resistant pipes consisting of a corrosion-resistant inner pipe and a carbon steel outer pipe that can withstand internal and external pressure. Potential applications for pipes with CRA material are subsea pipelines

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J uly 2015