^ A new autonomous subsea resettable valve
Article by Lucien Joppen
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Webtool has developed an autonomous subsea resettable valve for installation and use with a charged hydraulic fluid store. Easily activated by a steel wire rope line, the valve activation system is designed for applications where autonomous operation is needed in the event of an emergency.
Constructed from super duplex stainless steel enabling long term subsea deployment, the valve activator comprises a ball valve, a spring detention cartridge set to the appropriate activation force needed to allow the valve to open, and a activating lever that also functions as a removable rod arm. Charged with hydraulic fluid, when activated the rod arm rotates through 90 degrees causing the activator’s ball valve to rotate releasing stored hydraulic fluid, when fully open the rod arm is released. The valve activation device can be installed either left or right-handed.
The valve activation device is subsea resettable. It features a paddle which is rotated by ROV to the closed position and the system recharged. The rod arm is then pushed back into position by ROV, ready for re-use.
The valve activation system has been successfully deployed on a number of IWOCS emergency disconnection systems. Here the valve is activated by the movement of the Lower Marine Riser Package (LMRP) drifting away from the Blowout Preventer (BOP) on a subsea well. The movement of the LMRP overcomes the resistance of the spring detention cartridge.
Emergency disconnect systems have become crucial in mission-critical situations within the oil & gas industry. There are growing concerns over the cost of subsea intervention, together with the risk of asset damage in the event of an emergency.
Deployment of these systems results in a single cutting action, severing multiple hydraulic & electrical flying leads along with steel tension wire, within seconds.
As an integral part of an IWOCS system Webtool offers a simpler and quicker emergency disconnection than more complex multi-line stab-plate systems. It can be easily retrofitted and offers considerable space and weight savings. With a proven track record Webtool meets the ‘Technology Readiness’ requirements for deployment in subsea emergency disconnect systems.
Webtool’s emergency disconnection systems are also designed with corrosion resistant materials for extended periods of subsea deployment. This means that they are durable and offer a long service life. Their cutters can be easily function tested, ensuring they are always primed and ready for use. In general, the benefits of Webtool’s emergency disconnect system include a permanently installed cutter that doesn’t require any ROV time; easy integration within LWRP (Lower Workover Riser Package); single guillotine cutting operation, complete within seconds; no risk of the disconnect cutter jamming; hydraulic & electrical flying leads and tension wire all cut simultaneously; and no water depth limit.
Webtool cutters are standard equipment in most ROV fleets around the world based on their reputation for quality and reliability in demanding subsea environments.
Allspeeds has over 150 years experience in the design and manufacture of hydraulic equipment, and is perhaps best-known for their hydraulic cutters and systems, Tangye hydraulic lifting jacks and hydrostatic test pumps, Millingford sucker rod pumps, Kopp variable speed drives and Blake Hydram water pumps.
