Det Norske Veritas plays an important part in the safety work carried out at the Scanraff refinery in Lysekil, Sweden. Torkel Thornadtsson, manager of maintenance and projects at the refinery, which is owned by Swedish company Preem Petroleum and Norway’s Hydro,believes that an additional dimension has been added to the work since DNV came in.
Three DNV employees work continuously at Scanraff .The specialist expertise of the DNV laboratories in Oslo and the DNV networks in Sweden, Norway, the UK and other locations is also utilised. At the maintenance shutdown last autumn, 50-60 DNV employees with a wide range of expertise were in action for a four-week period.
The Swedish state-owned company SAQ that had a monopoly on independent inspections in its area until DNV took it over in 1999. At that time, SAQ and its predecessor, SA, had worked regularly for Scanraff since before construction of the refinery started more than 30 years ago.
Safe expansion and development
A lot has happened since then, and Scanraff has almost continuously expanded and developed the refinery. The result is better products, less pollution of the air and water and a healthy company with almost 600 employees. In October 2003, a gas recovery unit for vent gases from loading ships will be brought into operation in the product harbour, and the company has other major expansion plans in the pipeline.
Scanraff has a distillation capacity of 10 million tonnes of crude oil per year (210,000 barrels per day)."Almost 100% of the 35,000 m3 of crude oil we put into the refinery every day comes out again as finished semi-finished products. Very little disappears," says Thornadtsson.
Handling large quantities of oil products presents fire, safety and environmental hazards. The company has made large investments and carried out extensive training over the past few years to reduce these risks.
The refinery’s injury statistics are good. The sickness absence rate is low – less than 2.5 per cent. Some accidents and near-accidents – particularly among subcontractors – have given rise to concern and recent bicycle accidents inside the refinery have led to restrictions on the their use. However, the fact that Scanraff has its own cycle repair shop reveals that bicycles are still used a lot during the working day.
800 pressure vessels and 1500 pipelines
DNV’s work involves carrying out minor structural inspections, examining flow-charts, and checking that construction work and repairs take place in accordance with approved drawings and that non-destructive testing (NDT) is carried out as agreed. Most of the work is related to the annual inspection of 800 pressure vessels. In addition, 1,500 pipelines, with lengths varying from three metres to three kilometres, are inspected every third year. A total of 1,800 employees were involved in the maintenance shutdown last autumn – including some 60 DNV staff.
"We didn’t find any serious errors, but we took some replica samples to see if there were any structural changes in the materials," says Bernt Henriksson, DNV Inspection Engineer at Scanraff.
The refinery has its own inspection department, with inspectors for each of three plants. These carry out daily inspections and do what can be done by the company itself. All the DNV surveys are controlled by the Swedish authorities, while the new Pressure Equipment Directive (PED), which came into force in May 2002, applies to new acquisitions.
Risk Based Inspection
Scanraff knows that a safe and reliable plant is also a very profitable plant. In order to further improve safety and reliability, it has introduced Risk Based Inspection – RBI.
"RBI is one of Scanraff’s main goals in 2003, and is an issue at the monthly follow-up meetings at top management level in Scanraff," says Torkel Thornadtsson, who has almost 200 employees in his Maintenance and Projects unit. Scanraff got its RBI programme from DNV, and training involves DNV staff from both Sweden and the UK. "A lot of data is being gathered, and we aim to complete preparations for the on-site activities this year and follow up with the off-site work next year," says Thornadtsson, who knows that DNV-customers all over the world have a positive experience of RBI.
"It’s clear that the better the procedures we have for assessing risk the better the quality," says Thornadtsson. "DNV knows us and our plant very well after having been involved here since the start.That counts as a positive advantage."