Case Studies

Hydraulic Circuit Contamination


A UK based engineering company, our client supplies to OEM’s throughout the world and has a reputation for first-class service and quality.


The Problem

Our client was experiencing contamination issues with a hydraulic circuit, this was resulting in machinery downtime and could potentially have resulted in severe damage to their hydraulic system.

We were contacted to investigate the problem and working together, devise a solution to rectify the issue.



The Solution

Initially, oil samples were taken for analysis by our team, the report exposed metal particles were present therefore we quickly drained the 800 litre system and removed the inspection hatches to allow access to the reservoir.

The suction filters were removed & replaced, reservoir cleaned and the system pipework and hose assemblies also removed & flushed to NAS 6 cleanliness code.

The system was refilled with new Tellus 32 hydraulic oil using a 6-micron oil transfer unit.

Upon completion of the work, a package of offline filtration to include the inline high pressure duplex filtration stand (image below) was offered and subsequently installed.




Once the filtration stand was installed, the production downtime stopped, the filter arrangement also allowed the system to be ran at 60 degrees with a higher turbulent flow.

This ensured our client remained productive and also increased their efficiencies.



“This is a fabulous example of how our team can help with the more complex hydraulic problems, our many years of experience & knowledge has certainly helped our client on this occasion.”

Don Fenwick – HOS managing director


For information on hydraulic circuits or asset management, visit our services page HERE or contact us at

What Our Clients Say

We have worked with HOS for many years from small subsea cable ploughs to large J lay pipe installation towers, they are always willing to go above and beyond to meet our requirements & are experienced, friendly and willing to do what they can to help.

Lead Engineer – Multi National Maritime Solutions Provider

HOS offer a prompt supply service, along with technical assistance, quality is always at a high standard, we have developed an extremely good working relationship which we hope to continue to build on for future requirements.

Production Manager – National Engineering Company

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Administration & Marketing Manager – Engineering Solutions Provider

96 x 4SH hose assemblies – measured, tagged, pressure tested, flushed, installed and certified within 7-day window, Wow!

Ship Superintendent – Oil Rig Support Vessel

Thanks again for all your work on the recent project, great turn-a-round in less than a week for two complete marine hydraulic hose kits which were manufactured, pressure tested and flushed, complete with full documentation pack.

Head of Construction - International Subsea Engineering Company