TPI April 2009

Pipel ine products OCTG goods and

Market and technical trends in steel pipe coating The pipeline coating market expanded from 120 million m 2 in 2004 to 190 million m 2 in 2007, with a global annual growth rate of 15%, according to research conducted by Noru Tsalic at Applied Market Information. developed in the 1990s and comprise an FBE layer covered by an adhesive layer and a polyolefin. The FBE gives excellent adhesion to steel and the polyolefin provides a moisture barrier. The traditional multilayer PE application process can lead to a tenting effect in the weld region. The company’s new technology overcomes this, and the outer layer provides enhanced resistance to damage.

hardness, roughness, pull off and impact performance. Polyurethane is used as insulation on pipelines, for example subsea. Dow Hyperlast has new technology to reduce weight by 8% and improve thermal properties by 12.5%. Interface bonding, with the use of primers, can increase pull strength to 10 MPa. In the Northern hemisphere current Borealis Borcoat PE meets the challenges from -50° to +85°C. The Southern hemisphere requires a range from -30° to +90°C, with outstanding UV and mechanical resistance. The new Borcoat HE3450-H meets these demands. A new PE adhesive has been developed by LyondellBasell to improve bonding and widen the application window (it can be used in induction coil and flame heating systems). The company also has a top coat resin from multimodal HDPE with high safety margins. EUPEChasbeenexaminingPP insulation coatings and field joints. In water depths up to 500m a system of FBE, adhesive PP, solid PP, foamed PP and solid PP is used. For 3,000m more layers are required, for example a 7-layer system involving FBE, adhesive PP, solid PP and syntactic PP (with hollow glass microspheres). Joint systems include injection moulded PP (IMPP). Arkema has 40 years of experience with oilfield applications of polyamide 11. It has been used as a barrier layer in offshore flexible pipes, as a liner for sour gas, in gas pipelines in Australia for 35 years, in desalination plants, water and wastewater treatment plant pipes. The pipe surface must be prepared and primed and the polyamide layer ranges from 100 microns to several millimetres thickness. Evonik is another supplier to the industry and has looked at materials for rotational sintering, used in pipe lining. It produces polyamide 12 and PEEK which are very high performance polymers. PEEK can be used at temperatures up to 300°C and has high abrasion and chemical resistance. Bandera has developed machinery to reduce the use of polymer in pipe coating. Pipes are never completely straight so extra coating is used up where the pipe bends. Sensors are used

Polyethylene (PE) accounts for the majority of the market for polymers (over 350 kt), followed by polypropylene (PP) and epoxy (FBE). Asphalt is still used but generally now in more specialised applications such as under impinged concrete. Concrete is also used as a coating, for example for weight in negative buoyancy applications. The challenges for pipeline engineers are the increasingly aggressive contents and the harsher operating conditions for oil and gas. Cathodic protection is limited by the amount of current required, hence the need for coatings. This was discussed at the January 2009 AMI conference on Pipeline Coating, held in Vienna, Austria. Bredero Shaw and Shawcor are leaders in the field of pipe coating. Graded structure coatings were

Denis Melot of Total outlined the company’scurrentresearchandpractice: 3-layer PE is used up to operating temperatures of 80°C and 3-layer PP is used over 80°C and offshore, with heat shrink sleeves for field joints. There have been problems worldwide with coating disbondment, and Total is looking to remedy the situation. In Brazil, Andre Koebsch of Petrobras has worked with pre-qualification testing (PQT) of FBE coated pipeline. The pipe is checked for areas of disbondment, coating thickness, gouge resistance,

Brushes for weld cleaning Osborn International manufactures brushes and abrasives for use in the industrial, trade and private sector. Steel wire brushes are an ideal solution for the cleaning of welded seams. They are a cost effective and practical method for removing welding cinder and beads that prevent the next seam from being applied. The use of cellulose and alkaline electrodes are insignificant, as a brush will carefully remove all types of cinder.

A rotating wire brush will provide a clean welded seam without having to remove up to 30% of the welding material, as is inevitable with a grinding disc. Any defects in the weld seam also become immediately visible, enabling any rework to be carried out promptly.

Cleaning a welded seam using a S S rotating wire brush

The use of steel wire brushes reduces the number of seams by a claimed 30-50%, and additional time needed for resoldering work can be avoided. Whether weld cleaning, internal or external cleaning, bevel end cleaning, removal of insulation coats or rehabilitation work, Osborn pipeline brushes promise long life, optimal brushing results and safe work.

Osborn International GmbH – Germany www.pipelinebrush.com

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Tube Products International April 2009

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