Valves in action –
Bleeding and venting valve EB 3.52
Start-up bleeding for seawater extraction on a converter platform
Energy suppliers are increasingly turning to wind power to reduce climate-damaging CO2 emissions. In the North Sea off the German mainland in particular, numerous wind turbines provide green electricity. Three of these offshore wind farms supply energy to the German extra-high voltage network via one of the most powerful offshore converter platforms in the world. Its six steel legs are filled with gravel and sand for fixation, so that the floating platform remains stable in the water even in strong waves thanks to gravity.
The three-phase current from the wind turbines is converted into direct current on the converter platform, as this is the only current that can be conveyed to the coast via the almost 50 km long submarine cable without major power losses. A converter station on land transforms the direct current back into three-phase current and distributes it via a substation. In this way, more than one million consumers can be supplied with clean wind energy every year.
TASK // Start-up bleeding for seawater extraction for the desalination plant
A seawater desalination plant produces the water for cooling the machines and the drinking water on the platform. Submersible motor pumps are installed approx. 8 m below sea level to draw the seawater. These have a delivery rate of approx. 50 m³/h and pump the seawater onto the platform via a pipe section at a height of approx. 22 m. The EB 3.52 start-up bleeding and venting valve removes the air from the system when the pumping process is started.
SOLUTION // Bleeding valve from Super Duplex for start-up operation
With its sturdy design, the EB 3.52 float-controlled bleeding and venting valve is the ideal solution for the highly corrosive, harsh maritime environment of the converter platform and the oily water in the pump circuit. Due to its large seat cross-section, it can discharge big quantities of air at low pressures during the start-up process of the submersible motor pumps. The valve closes reliably as soon as it is filled with liquid and opens when the level drops, with simultaneous pressure relief. The body of the EB 3.52 is made of Super Duplex (1.4501), the solid float from polypropylene. The medium-wetted parts are designed according to the Norwegian standards for the oil and gas industry NORSOK. The Mankenberg profile clamp system allows for convenient maintenance.
