Hydraulic cylinders help mooring tensioners withstand harsh conditions

In order to keep gas production on track, bespoke mooring tensioners were recently required for a floating liquefied natural gas (FLNG) compression and storage vessel off the coast of West Africa.

Due to the extreme environmental conditions, the manufacturer of the mooring tensioners turned to long-term technology partner Eaton and its XL hydraulic cylinders. Eaton needed to supply a bespoke solution for the unusual mooring system compensating for the motion of waves, where the XL cylinders were in an atypical horizontal orientation.

Design and manufacturing work took place at Eaton’s Eindhoven facility in the Netherlands. There, the company added its Eatonite, its proprietary cylinder rod coating. The coating system is said to offer superior corrosion resistance in saltwater operations.

Eaton says that it also integrated a stroke measurement system, further enhancing the performance and safety factor of the mooring tensioners. The system enables the customer to know the position of the piston in the cylinder and accumulator at any moment. This capability also allows the early identification of any accumulator leaks, making it possible to deal with issues promptly. Without such a system, the first sign of a problem would be performance loss, or even sudden failure.

With just a 10-month lead-time, Eaton’s Eindhoven facility designed and delivered 12 mooring tensioner XL cylinders in carbon steel with built-in accumulators. Featuring a 600 mm diameter and 4500 mm stroke length, these hydraulic cylinders have a design pressure of 230 bar (3335 psi). Each one is also equipped with stainless-steel piping and manifold blocks.

By combining corrosion protection with a sealing system, Eaton’s solution is said to be able to withstand the application’s tough environment, substantially extending the lifetime of the mooring tensioners and enhancing operational safety.