Apex Hydraulics won the tender to repair 32 linkspan finger cylinders and two separation deck cylinders for a berth in a large UK port.
As part of the repair specification, Apex had to replace the piston rods in all the cylinders including the specialised ceramic coated separation deck rods.
Several years earlier, the dock had commissioned Apex Hydraulics to make some temporary repairs to last for a short period. These temporary repairs had already been in place for several years, and the port was now ready for more durable, long-lasting repairs, to bring the cylinders back in line with their Original Equipment Manufacturer (OEM) specification.
Full specification repairs over a temporary fix
Because Apex Hydraulics had previously completed the temporary repairs, all of the measurements and drawings were available in the Apex design office. This allowed Apex engineers to manufacture the 32 rods prior to the damaged cylinders coming in for repair, vastly cutting the turnaround time, and meaning that the dock could expect a much shorter down time. The customer was given a guarantee that the 34 hydraulic cylinders could be stripped, assessed, have rod and bearings replaced along with any other standard repair processes, finished off with a full hydraulic pressure test and off-shore paint system– all within a four-week window.
Complex ceramic rods with integrated measuring system
Whereas the 32 finger cylinders had chrome plated piston rods, the two separation deck cylinders featured a specialised ceramic coating. These cylinders also incorporated cylinder position technology with a rod integrated measuring system.
This type of system functions using proportional valves, which are used to slow down or speed up cylinder movements. In order for this to work a measuring system identifies exactly where the cylinder is at all times.
The integrated measuring system works by reading the undulations in the substrate of the base material. As it is not possible to chrome plate a cylinder that has these precise grooves along the entire rod length, the rod is sprayed with ceramic which infils around the grooves and this can then be ground back to a nominal diameter to the required surface finish. The specialised sensor is capable of reading through that ceramic layer and to the substrate below. The control system uses these sensor readings to give a live read out of the cylinder position at all times.
The ceramic coating was failing on the separation deck cylinders, so using the historic drawings from previous repairs, Apex manufactured two replacement rods (complete with the rod integrated measuring system and ceramic coating) to the OEM specification. These new rods were completed and ready at the workshop, prior to the damaged cylinders coming in, so that they could be fitted as part of the repairs without any delay. This allowed the repairs to be completed within the required four-week window.
Apex Results
These 34 cylinders are now back on the dock linkspan, and this time they will be able to keep working for up to several decades before major repairs are required. The port is delighted with the quick turnaround on the repaired cylinders, which has meant very little down time for the dock.
For more information on ceramic coated piston rods, with or without integrated measuring systems, or any other specialist hydraulic cylinder manufacture or repairs, contact Apex Hydraulics today on 01924 456788.
Related Products
The following products were utilised as part of this project. For more detailed information on these products, click on an image below…
