Oil Filtration

SDU H-350 UW

The SDU-H350-UW-S is the latest derivative of our subsea filter. The main purpose of the filter is to keep water contamination at bay, allowing the ROV to work reliably for extended periods without the need to return to surface. Keeping an ROV’s hydraulic systems dry ensures the lubrication and dielectric strength properties of the oil are maintained, avoiding costly component failures.

Designed to be installed on an ROV, the unit features 316S stainless steel fittings throughout, and the filter housing has a non-reflecting hard anodised surface finish (designed to eliminate flare from lighting and also to provide protection against corrosion). As well as ROVs, the SDU-H350-UW-S is also often selected for other marine applications where corrosion resilience is key. We are proud to supply our subsea filter units to many ROV OEMS for factory fit.

Using a CARDEV SDFC filter cartridge, water and particle contamination (causes of 95% of hydraulic breakdowns) are removed, leaving your oil “cleaner than new”* – ISO Code 15/13/9 and >0.05% RH moisture content.

*For more info on cleanliness classes see our guide to contamination; “How clean is clean?”




  • Removes water contamination maintaining oil in “cleaner than new” condition
  • Oil filtered whilst the ROV runs – clean the entire system, not just the oil in the reservoir
  • Improved ROV reliability and availability
  • Reduced carbon footprint = lower operating costs:
    - Extended oil life = reduced oil    
      purchases, downtime & servicing 
    - Reduced waste oil  = reduced waste
       handling costs
    - Reduced component wear =
       increased machine reliability &
       availability and reduced maintenance 
  • Simple installation


  • Pressure compensating flow control valve – 2l/min flow rate
  • Input pressure 5-350 Bar
  • Sample point – allows for remote pressure gauge fitment
  • Bleed valve to purge air from system after filter change
  • BSP / Metric / JIC fitting options
  • 316SS fittings
  • Hard anodised housing


Customer quotes

“We had to make an emergency repair and get the ROV back in the water again, even though the oil was milky in appearance due to water contamination. When the ROV was brought back to the surface CARDEV had turned the oil from milkshake to Cognac!”
Large ROV operator, Norway

“It’s easy for people to forget, but before we had CARDEV filters fitted to our ROVs we rarely achieved 1000 hours before major hydraulic component failure”
UK ROV operator

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