Trelleborg Launches Subsea Vibration Suppression System

Trelleborg’s offshore operation  launched an innovative new vortex induced vibration (VIV) suppression system. The Tri-Strake Combi, developed to complement the high performance S-Lay capable Tri-Strake Stinger system and the cost effective Tri-Strake Lite system, not only eases installation but provides added resilience and load bearing capacity, including stinger installation loads.

Jonathan Fox, Senior Product Development Engineer for Trelleborg’s offshore operation, said: “Pipelines unsupported over free spans, such as steel catenary risers and rigid steel flowlines, are prone to VIV fatigue, which can lead to serious issues such as pipe girth weld failure or premature pipe malfunction. To combat this, the Tri-Strake Combi comprises interlocking moldings, with three-start helical strakes.”

Trelleborg utilized its vast offshore and VIV knowledge in the design of the Tri-Strake Combi and carried out extensive computational analysis and physical testing. The system’s lightweight construction provides operators with a simple and rapid assembly method. While the customized high endurance material selected for the system not only provides added resilience and load bearing capacity, it also eases installation.

Each section of the system has been designed as a lightweight hinged component, ensuring it is quick and easy to pre-install onshore or install offshore. The unique, modular design enables the system to be stacked during shipping, ensuring more efficient and cost effective transportation.

Trelleborg’s innovative manufacturing process also means that the Tri-Strake Combi can be produced up to three times faster than systems manufactured using traditional techniques, reducing tool turnaround and manufacturing times.

Fox, added: “The Tri-Strake Combi was developed in response to market demand for a high quality, cost-effective VIV suppression solution. Using an established manufacturing technique we were able to meet these demands by using rapid manufacture leading to quick installation times and reduced transportation costs.

“Working with polymers across a number of technologies and industries, we were able to use our insight and innovation to improve VIV suppression performance using best-value engineered solutions.”