Swedish Trelleborg, has developed an innovative new distributed buoyancy module (DBM) clamp that offers technical, commercial and schedule advantages to provide offshore operators with a more cost-effective and compliant solution.
Austin Harbison, Product Development Manager with Trelleborg Offshore & Construction, commented: “As a key element of subsea operations, DBMs play a vital role when it comes to maintaining the configuration of flexible risers and umbilicals, ensuring fatigue damage and stresses are minimized. However, an increase in operating temperatures, combined with the use of ever more complex riser systems, has resulted in offshore operators requiring increased compliance and higher capacity from their buoyancy solutions.
“Understanding the significance of buoyancy clamps when it comes to guaranteeing optimum performance, we took the decision to enhance our DBM clamp range. Utilizing an superior composite construction, it ensures easier and safer working conditions, but also greater compliance and design assurance for the offshore operator.”
Simplified manufacture & lead time reduction
Providing an increase in clamp capacity, Trelleborg’s new DBM clamp offers improved compliance to better accommodate riser creep. Furthermore, the new clamp, which offers a universal interface for use on all riser types, now features aramid fibers in place of a fabricated titanium strap.
This development has resulted in simplified manufacture, as well as a significant reduction in lead time; lead times for clamp components such as straps are now reduced to days rather than months. In addition, the new lightweight design means the clamp is more buoyant and lighter in the air, therefore assisting with handling and installation.
Harbison, continued: “One of the primary considerations in the development of our clamp was to phase out the titanium straps, due to their cost, weight, complex manufacture and associated lead time. As such, we took the decision to replace the titanium previously used with continuous aramid fibers, offering a wealth of benefits for the operator.
“This is actually the first phase of our ongoing development for this product range as we introduce aramid fibers and a standard user interface. We are passionate about continuous innovation and as such, dedicate significant time and resources into developing solutions which are specifically designed to meet the ever-changing wants and needs of the offshore industry – we are confident that our new clamp range will be well received by the sector.”
As well as enhancing its clamp design, Trelleborg recognized the need for improved installation tooling and has introduced a new range that dramatically reduces tool cost and weight, and improves speed of installation.
The weight of the new tooling solution has reduced by 90%. Furthermore, when using this new range, clamps can be installed in 50% less time than with previous systems.
“With tool design independent of riser type, our lighter, more automated installation tooling range is much safer to use, and when combined with the new flexible clamp, helps to speed up installation, saving vessel time for customers,” concluded Harbison.
To provide customers with better design assurance when using the new clamp, Trelleborg has integrated experimental stress analysis to provide a high resolution of information to correlate with both FEA and analytical calculations.