The Class 1-4 Rotary Docking Jupiter Electric Torque Tool (ETT) has successfully completed an offshore task to free two seized valves in the North Sea.
The Jupiter ETT, belonging to Ashtead Technology, a leading provider of subsea technology and services, was interfaced to a Saab Leopard ROV and operated by a global provider of ROV and hydrographic services.
The client had recently discovered damage to a subsea pipe on a gas installation. To investigate the extent of the damage, the ETT was deployed to close two API 17D style subsea valves, allowing the client to pressure the line and observe for potential bubbles evacuating the pipe. The valve spec stated a breakout torque of 126Nm, however due to the length of time since they were last operated, both valves had seized.
On deck, calibration tests proved that the ETT was accurate, which provided the client with the confidence to increase the torque applied to approximately 200% of the specified breakout torque, just 15% below the specified damage torque of the valves.
During the procedure, the ETT slowed and stopped several times due to ‘sticky zones’ within the valve stem. To allow for operations to continue smoothly, the ‘pulse’ operation mode was activated, which enabled the tool to apply and remove a defined torque repeatedly without user input, and without the applied torque increasing above the limit implemented by the client. By using this feature, the valves were freed up allowing operations to continue.