The Subsea version of the new SPX hydraulic tensioners, the SST range, is designed to resist the most extreme working conditions of use which guarantees the product's durability and performance. The tools are coated with a high-quality nickel plating which enables them to resist any salt-water environment.
Very compact and easy to use, SST subsea hydraulic bolt tensioners enable the tools to be used simply by placing the body over the stud/nut and sliding the ‘open’ ‘quick reaction nut’ along the thread and onto the tool. A simple squeeze click engages it securely onto the thread which is locked on when pressurizing the tool ; removal is in reverse, which simplifies operations and minimizes the divers' worktime. Like the Topside versions, SST hydraulic tensioners are equipped with an integrated misalignment compensator allowing a stud deviation of up to 5 degrees and a piston stroke limit indicator, allowing for controlled and synchronous operation.
Moreover, the piston has a 30mm stroke in order to close/load the flange in a single operation, reducing the possibility of the overstroke of individual tools.
For the operator's complete safety the design of the SST hydraulic tensioners prevent piston ejection and avoids any oil release to the environment.
The different models in the range offer a capacity ranging from ¾ to 3 ½ inches (M20-M90), operating with a maximum pressure of 21,750psi/1,500 Bar. SST underwater hydraulic tensioners are used with QRN quick-release reaction nuts from SPX Bolting Systems.
When working in restricted access or ‘blind’ applications, it is sometimes difficult to apply the necessary pre-stressing to the nuts using traditional fasteners or tools (in these cases you can choose a hydraulic nut). EHN, the new generation hydraulic nut is used in this case by replacing it for the hexagonal nut and it then remains with the stud. The preload of the hydraulic bolt is carried out by a pump (manual or air) and mechanically retained by screwing down a threaded collar, the pressure is then released and the locking is complete. The fastener becomes permanent and proves to be an ideal solution for tight spaces where a bolt tensioner or torque wrench cannot be used.
Manufactured with precision, EHN is a fast, accurate and cost-effective solution for single application or multiple bolted joints and offers the following advantages:
• Compact enough to adapt to the tightest application
• Maximum load produced at 1,500 Bar (21,750 psi)
• Energized by either a manual or air-driven hydraulic pump
• Made-to-measure hydraulic nut design within a very short time-frame
• Different types of collars and bases are available • Wide range of threads from 3/4" to 6" (M20-M150)