Products and solutions, 2007-02-27, 01:35 PM
Shutdown in the shadow of the “seven sisters”
Without any accidents, without leakages during start-up, without quality shortcomings, on schedule and within the budget went a shutdown ahead at Esso’s Fawley plant near Southampton on the English south coast, the biggest refinery in the United Kingdom and one of the best-known in Europe. ThyssenKrupp Xervon participated as leading industrial service provider, responsible for all necessary repairs coordinated and implemented at two important parts of the plant.
The refinery with its own port is situated on the English Channel coast in the shadow of the “seven sisters”, seven large pressurized spheres in which butene is stored. Each year about 2,000 ships pass this landmark and turn over about 22 million metric tons of crude oil and other products in Fawley. The refinery processes about 330,000 barrels of crude per day and accounts for about 15 percent of petroleum products in the UK.
When a plant of this magnitude undergoes a general overhaul, it’s “All systems go!” for everyone concerned. And this also applied to ThyssenKrupp Xervon, which accompanied shutdown operations in two decisive parts of the plant, the Poly Plant Block and the FCCU Plant, from October 2 to 26, 2006. In a total of over 35,000 man hours, about 130 men were in action to safely and skillfully accomplish the major shutdown within the extremely tight schedule.
This was an opportunity not only for the company, but also for its employees to demonstrate their expertise in the inspection, maintenance and repair sector. The industrial service providers are responsible for analysis and planning, carry out maintenance, conversions and repairs, take care of parts and materials handling, and organize shutdowns worldwide without outside supervision. When manpower shortages arise at short notice, Xervon can draw at any time on a pool of expert staff with the requisite specialized skills thanks to ongoing in-company training. These men are fully conversant with plant assembly, pipeline construction, apparatus repairs, materials handling, drive technology, electrical, measuring and control equipment, warehousing, and purchasing. In the case of Esso in Fawley, the shutdown team brought together German and Hungarian experts. The official site language, however, was of course English.
Language coordination was a huge challenge for the Xervon project managers, who provided not only the senior management for the shutdown of the two parts of the plant, but also the supervisors and staff for administration, planning and execution. Along with the overall planning of the project, Xervon was also responsible for the coordination of the ancillary trades (scaffold erection, insulation, cleaning, corrosion protection, inspection etc.) and for the post-shutdown phase. Esso’s praise is therefore appreciated all the more. Rob Tarbard, Fawley's head of turnarounds said: "Xervon did an excellent job on our turnaround, demonstrating high levels of safety and a positive approach to all aspects of the work - we were very impressed."
Duplex: The challenge of pipeline construction
While the replacement of two superheaters at the waste heat boilers, plus the ancillary trades, was carried out and supervised at the FCCU plant with its catalytic cracker, most of the attention was claimed by the Poly Plant Block. This block consists of heat exchangers, tanks, columns, over 100 pipelines, and over 200 fittings and valves. Xervon’s task was to technically overhaul the apparatus and remove and replace all the faulty parts as well as organize all the mechanical work in coordination with the other trades. In addition to extensive work on fittings, the major focus was on pipeline construction. This was a challenge not only because of the sheer volume of work, but also because of the materials themselves. Some of the pipelines are made of duplex steel, which calls for very slow welding with thin electrodes because the material has to be repeatedly allowed to cool off to prevent it overheating. The welders need their full concentration for this, because “as soon as blue tarnish appears on a duplex weld, the seam is useless,” explains Xervon Project Manager Stevan Wallhäusser.
As an experienced maintenance specialist, the Gelsenkirchen company has already aided Esso with shutdowns in Ingolstadt (Germany), Antwerp (Belgium) and Rotterdam (Netherlands). “This experience proved very useful during preparation and planning in Fawley,” explains Wallhäusser. All the more so, as the usual deadline pressure was supplemented by extremely tough safety requirements. For instance, no work could be carried out until completion of a risk and safety analysis like the Task Risk Assessment (TRA) and CARE (safety check before the start of work). On top of this, there were also strict environmental regulations to be observed. Esso has committed itself in Fawley not only to protecting the natural environment, but also to promoting it and is keen to publicize the fact that the service water is cleaner after processing than before use.