Bosch Rexroth’s subsea clamping cylinder for fully automatic bend stiffener connectors (BSCs) is designed for use for up to 25 years and offers high clamping forces, a powerless holding operation, and easy installation with no need for manual work by divers.
The patented automation solution withstands forces of up to 120 tons per clamping cylinder. A cushioning mechanism absorbs vibrations and distributes the load across a number of cylinders within the system, preventing material fatigue and premature wear with a predefined clamping force. The integrated clamping unit allows straightforward, reliable actuation during commissioning and removal, even after long periods of use.
BSCs protect riser systems against premature material fatigue coming from movements such as those caused by waves. This helps protect valuable investments and increases the availability and productivity of the offshore equipment. In a fully automatic BSC, a number of Rexroth clamping cylinders are used as a system.
The cylinder protects riser systems against bending loads and allows a secure and economical holding operation. Holding operation requires no power; a hydraulic supply is only required for the initial clamping and subsequent removal. Bosch Rexroth offers an optional integrated hydraulic power unit with electrical control systems for this purpose.
While the rated force is being set hydraulically, a spring in the cylinder is tensioned and fixed using a safety lock unit. This allows the clamping force to be maintained over the entire operating time in a purely mechanical manner, with no need for a continuous hydraulic or electrical power supply.
Thanks to the combination of flexible mechanical and hydraulic force components, loads that act in all six degrees of freedom are automatically distributed to the subsea clamping cylinders installed in the system. Each individual cylinder can withstand up to 120 tons. The flexible load distribution allows a much longer operating life and higher system availability.
The design of the subsea clamping cylinder takes into account the entire usage cycle. Until the system is installed, it can be stored under water at a depth of up to 3,000 meters for two years. The clamping unit can be hydraulically released and controlled easily, safely, and reliably for removal or further use.
The subsea clamping cylinder can be used in other clamping applications, not just in a marine or offshore setting but on land too.
Bosch Rexroth offers online training for interested engineers and users.