A novel remote hose disconnector from hydraulics specialist Enerpac aims to eliminate the release of hydraulic fluid into the sea during the installation of transition pieces at the base of offshore wind towers.
The environmentally friendly development – which allows full recovery of all connected equipment for reuse – will be useful in a large number of impending offshore wind farm developments in Australasia and the Asia-Pacific region.
Enerpac Asia-Pacific Marketing Manager Antony Cooper points out that hydraulic cylinders are a key tool in the installation of the transition piece on monopile support structures at the base of wind towers, with up to six fixation cylinders used to hold the transition piece in position during grouting.
These cylinders have to remain pressurised, via a hydraulic manifold, during the grouting and the subsequent curing time, which can be up to several days. At the end of this period, the cylinders and hoses need to be recovered.
“Until now, cutters have been used to cut the hose to depressurise the cylinders, releasing hydraulic fluid into the sea,” says Cooper. “Using the Enerpac remote hose disconnector will allow the cylinders and hoses to be depressurised and recovered without hydraulic oil being released into the sea, as well as, avoiding the need to use a hose cutting tool and associated waste materials.”
The remote hose disconnector is fitted directly onto each fixation cylinder. It comprises two, noninterchangeable, hose connections: one connector ensures oil flow to the fixation cylinder, the second one operates the disconnector itself.
After the grouting has cured, an Enerpac pump is connected via the same manifold with the second set of hoses. Operating the pump recovers all hydraulic oil and ensures full retraction of the plungers. The complete hose disconnector is then released from the fixation cylinder and ready to be re-used to install a new foundation.
During the disconnection, no fluid is spilled into the sea. And any potential residual oil in the cylinders is sealed from making contact with seawater, making this method fully sustainable.
Patrick Frencken, Key Account Manager North West Europe, Enerpac, says the Enerpac Remote Hose Disconnector marks an environmental breakthrough in the installation of monopile and transition pieces. He adds: “Installation companies can extract maximum operational and environmental value from the remote hose disconnector, and fully recover it for reuse.”
The Enerpac remote hose disconnector has been tested and certified by Lloyds to 100m subsea and can be reused.
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