A wire line tensioner system is used to ensure a pre-defined tension to the marine riser and to compensate any rig motions like heave, roll or pitch. An accumulator loaded hydraulic cylinder generates the tension in a pulley system which is connected to the drill rig structure on one side and to the tension ring on the other side.
Because the hydraulic cylinders are installed on the platform deck free access for service and maintenance is given. To protect the piston rod against corrosion, Nickel-Chrome layers or thermical sprayed coatings are used. Hunger DFE seal and guiding elements are used to provide long life properties. The cylinders can be delivered with mounted accumulators and piping. Certification according to DNV lifting appliances 2008, DNV standard for certification No. 2.9 hydraulic cylinders and DNV offshore standard E101/D101 or alternatively according to ABS rules for building and classing, steel vessel. Part 4, Lloyds register, GL or Bureau Veritas.