HPU · Marine

Overhaul of a steering gear HPU

Full recovery of the hydraulic power unit driving the rudder, with pump replacement and contamination brought back within specification.

Discipline
HPU
Sector
Marine
Location
Shipyard — Rio de Janeiro (RJ)
Year
2024
Duration
11 days

Objective

The problem that prompted the intervention

The vessel was losing rudder response speed progressively and the fluid was running abnormally hot. The client needed the operating condition restored within the docking window already contracted, without extending it.

Contracted scope

  • Diagnosis of the steering hydraulic system
  • Full overhaul of the hydraulic power unit
  • Recovery of the rudder actuator cylinders
  • Replacement of filter elements and hydraulic fluid
  • Flushing of the pressure and return lines
  • Commissioning and operational testing with the crew

Execution

The sequence applied and the engineering decisions taken

The order below reproduces how the work was actually carried out, including the points where the condition found required a change of scope.

  1. Pressure, flow and temperature readings taken in operation to characterise the fault before strip-down.
  2. Fluid analysis, which showed a contamination level far above that specified for the system's proportional valves.
  3. Strip-down of the HPU with photographic records and identification of every component and connection.
  4. Dimensional inspection of the piston pumps, which showed wear on the valve plate and slippers.
  5. Recovery of the actuator cylinders: tubes honed, rods ground and re-chromed, seal sets fully replaced.
  6. Replacement of the main pumps and overhaul of the proportional valve block.
  7. Flushing of the lines until the specified cleanliness class was reached, tracked by sampling.
  8. Reassembly, leak testing and commissioning, with response times verified to port and starboard.

Comparison

Condition before and after the intervention

Drag the slider to switch between the two recorded conditions.

Condition of the equipment after the intervention
Condition of the equipment before the intervention
Before After
Before
Slow rudder response, fluid above working temperature and contamination outside the specified class.
After
Response time to design specification, temperature stabilised and fluid within the required cleanliness class.

Result

What the intervention delivered

The system was handed back within the response time specified in the design and with the working temperature stabilised in the normal band. The work was completed before the docking window closed, releasing the vessel on schedule.

11 days on the job
100% within the docking window
2 cylinders recovered

Photographic record

Job gallery

The photographic record forms part of the technical report handed to the client and feeds the equipment history.

Portfolio

Other completed projects

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Technical support

Need to bring a piece of equipment back into service?

Tell us the condition of the equipment and the window you have available. Our engineering team will come back with an assessment and a preliminary scope of work.

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