Products and solutions, 2010-09-14, 11:56 AM
The right answer to any anticorrosion challenge
Corrosion-protection jobs at the Frankfurt-Höchst industrial park are among the specialties performed by the Raunheim base of ThyssenKrupp Xervon. This local service provider has been commissioned to carry out numerous quite dissimilar yet complex coating jobs by both the park operator Infraserv Höchst and other companies located on the site. Its most recent project was to apply the very first coating to two nitrogen storage tanks without in the process erecting any scaffolding and to apply comprehensive erosion protection on the 140 m long pipe bridge at a new plant.
The Frankfurt-Höchst industrial park measures over four square kilometers; it provides space for over ninety companies with around 22,000 employees. To keep the plants in good condition calls for professional anticorrosion solutions including “specials.” For the external coating of two new steel tanks, the plan was to dispense with the surrounding access scaffolding normally used for such work. This was a genuine challenge on tanks with an outside diameter of 15.7 m and a height of 16 m. Required was a cleverly conceived procedural strategy and the right equipment. Latter included a large telescoping platform (cherry-picker) and a high-pressure water-jet pump (2,000 bar) in order to prepare for the triple-layer epoxy resin coating on the surface of the tanks welded from double-walled elements.
The coatings were applied from the cherry-picker, manually with the aid of 25 cm wide rollers. In the first phase, the welding seams were primed, then the entire tank. Then an intermediate and finally a top coat were applied to arrive at an epoxy-resin coating of around 240 µm. All this took up time since the team of three coaters working on the telescopic platform had to approach and work on each tank element a number of times.
The twenty working days estimated in the preparation plans proved realistic even though the final job, the application of the corporate logo, proved another challenge all of its own. The logo measured 3.60 m in height and 5.60 m in width. It, too, was applied without the help of any scaffolding, simply from the cherry-picker. Xervon’s solution: from the cherry-picker, separate precisely measured sections of plastic film were stuck to the tank surface to display a negative of the desired geometry. The exposed surfaces were then painted and the plastic stripped to yield the perfect logo.
Professional protection for pipe bridge
Likewise complex was the first coating for the 140 m pipe bridge that supplies the Ticona plant to be commissioned in 2011, with a variety of media and energy. Around 11,000 m edging and 4,000 m² surface had to be given a triple coating of (2-component epoxy oxide resin-based material) for corrosion inhibition. The special aspect: prior to each coating, the bridge surface had to be carefully cleaned by steaming. This removed any possibly existing chloride that might have been deposited on the pipe bridge due to the salt hopper close by. The work called for vast care and flexibility since it had to keep precise pace with that of the pipe installers, step by step manually using brush and roller.
Prior to each step, the next section first had to be steam cleaned and then coated, all on the same day. Otherwise there was the risk that overnight salt might deposit on the bridge and impair the corrosion protection. In order to provide long-term protection, the structural steel workers had already applied a primer during the pre-assembly phase. Then ThyssenKrupp Xervon applied a second primer followed by a thicker intermediate layer and the final top coat to give a total thickness of 300 µm.