Apex Hydraulics specialise in the manufacture of bespoke hydraulic cylinders for a wide variety of applications. With an expertise in producing hard wearing cylinders for difficult environments, they are often approached by the offshore and subsea sectors, to manufacture robust hydraulic cylinders for machinery that is required to be particularly durable. The offshore sector has the complexities of a corrosive saltwater environment, as well as a high risk of strong currents, wind and waves regularly battering any machinery. Many cylinder failures in these kinds of environments are caused by pitting and cracking to cylinder rods, allowing contaminants into the hydraulic fluid. Apex Hydraulics specialise in bespoke rod coatings and cylinder designs, to ensure that their hydraulic cylinders are among the most robust and long lasting available to buy.
A client commissioned Apex to manufacture 15 cylinders for a subsea plough. All the cylinders were to be built with linear transducers in order to closely control each cylinder stroke.
A Complex Fabrication
A subsea plough is a complex offshore tool typically requiring a range of cylinders. The cylinders must be able to judge the depth of the seabed, raising and lowering the plough accordingly.
Subsea ploughs work on a wide variety of different projects. For example, when electric cables need to extend from wind turbines back to the on-shore facility, this cable must be buried in the sea bed to avoid any risk of it causing harm to ships or wildlife, or getting damaged by currents. A ship with a LARS will connect the cable at the turbine, and then pull the plough; burying the cable as it moves forwards. The front of the plough will cut a big trench in the seabed. The cable will be laid into the trench and the back of the plough will push the seabed back over the cable. A subsea plough can be used with any vessel that has a LARS.
Repair and Manufacture
Apex is familiar with the repair and maintenance of these cylinders, which must be recommissioned every several years as part of the company’s maintenance programme. Apex can strip and assess any failed cylinders so that engineers can pinpoint and improve upon any flaws.
Apex also manufacture new subsea plough cylinders; designed with Apex’s usual attention to detail and innovative solutions to overcome the harsh environment that offshore and subsea equipment is subject to. Each set of cylinders is manufactured to the specifications required for the machine.
For this commission, Apex design engineers built the cylinders to the measurements required for the machine, using details provided by the client. As with all cylinders for subsea ploughs, the cylinders needed internal linear transducers complete with SubConn electric connectors. This allowed the hydraulic cylinder to automatically extend the stroke to the exact measurements required, with an accuracy of less than a millimetre.
The rod was stainless steel chromed to make it resistant to the high salt environment and the wind and waves, with three coats of subsea paint to ensure a long-lasting finish.
Apex Results
Apex manufactured the cylinders to time and with rigorous testing and inspection, to ensure that the cylinders meet the exacting standards required. The clients were provided with certificates of conformity. Apex is able to facilitate testing and certificates of conformity for any third-party inspection agencies as required.
Related Products
The following products were utilised as part of this project. For more detailed information on these products, click on an image below…
