Worker mixing liquid metal in a furnace

Shell Fire-Resistant Hydraulic Fluid S2 DU

Melted metal inspected by a worker


Enhance the protection of your hydraulic systems

Keep your systems running smoothly and safely while reducing the environmental impact of your operations.

Hydraulic systems operating in industrial and marine settings – along with mobile set-ups – often need specific protection that goes beyond preventing component wear and equipment breakdown.

To run efficiently in conditions that can range from moderate to severe, they also need lubrication that improves safety through increased fire resistance and enhances the protection of local ecosystems.

Shell Fire-Resistant Hydraulic Fluid S2 DU is based on synthetic organic esters and is an FM Approved Fire-Resistant industrial fluid that provides enhanced protection, alongside excellent anti-wear properties.

Performance Advantages

Worker at a furnace pouring melted metal

Deliver peak performance in extreme conditions

With a higher autoignition temperature and greater heat release compared with traditional mineral oils, Shell Fire-Resistant Hydraulic Fluid S2 DU reduces the risk of fluid ignition and is ideally suited to operating environments subject to fire hazards, such as steel mills, surface mines, foundries, tunnel boring and other metal, mining and glass industries.

Shell Fire-Resistant Hydraulic Fluid S2 DU is a versatile fluid designed to reduce fire risk and enhance system efficiency and hydraulic equipment wear protection across a range of challenging operating environments

Excellent cleanliness and filterability characteristics, and excellent water separation, air release and anti-foaming properties help to keep hydraulic systems clean and running smoothly, even if the fluid is contaminated with water.

Environmental Advantages

Old mine in coastal setting

Protect your equipment and the environment

When operating in environmentally sensitive settings, you need to know that your hydraulic fluids are not only able to protect your equipment but also help you to mitigate any impact on local ecosystems.

Shell Fire-Resistant Hydraulic Fluid S2 DU is engineered to work in a wide range of settings and has been designed with the environment in mind

  • It is classified according to OECD and EPA water-accommodated fractions test guidelines as “not harmful” to bacteria, algae, freshwater and marine invertebrates, and fish.
  • The fluid is also readily biodegradable (more than 60% broken down after 28 days in the OECD 301 B carbon dioxide evolution test)
  • And contains a mean biobased content of over 80% (ASTM D6866).

The low toxicity of Shell Fire-Resistant Hydraulic Fluid S2 DU, when compared with mineral oils, makes it particularly suited to environmentally sensitive areas where fire hazards are also a concern. These include industrial, marine and mobile applications.

Service Life Advantages

Liquid metal furnace using water

Lower operating costs and reducing downtime

Shell Fire-Resistant Hydraulic Fluid S2 DU provides anti-wear and film strength properties necessary for hydraulic systems under moderate to severe conditions. Shell Fire-Resistant S2 DU advanced ashless and zinc-free anti-wear additives protect against operational wear:

  • As proven in Eaton Vickers 35VQ25 vane pump and Komatsu HPV35+35 high-pressure piston pump tests.
  • Shell Fire-Resistant Hydraulic Fluid S2 DU has lower wear compared with the Eaton Vickers V104C pump test limit (ISO 20763) and provides better wear protection than industry standards and mainstream mineral oil hydraulic fluids.

Improving Air release - Air in the oil can lead to undesirable consequences such as reduced efficiency and responsiveness and increased likelihood of erosion, cavitation or other harmful system issues that can cause unplanned downtime and increased maintenance costs.

  •  Shell Fire-Resistant Hydraulic Fluid S2 DU exceeds equipment manufacturers’ air release limits.

Designing fire-resistant hydraulic fluids with reduce wear protection and improve air release helps to extend the life of components and service life of your equipment. It improves the efficiency of your hydraulic systems and keeps them running for longer.

Method ISO 46 ISO 68
ISO viscosity grade 46 68
ISO fluid type ISO 6743-4 HEES/HFDU HEES/HFDU
Kinematic viscosity at -20°C, cSt ISO 3104 1,522 2,640
Kinematic viscosity at 40°C, cSt ISO 3104 47.2 67.7
Kinematic viscosity at 100°C, cSt ISO 3104 9.41 12.3
Viscosity index  ISO 2909 188 183
Density at Kinematic viscosity at 15°C, kg/m³ ISO 12185 921 924
Fire point, °C ASTM D92 372 371
Flash point (Cleveland open cup), °C ISO 2592 320 320
Autoignition temperature, °C ASTM E650 400 -
Pour point, °C ISO 3016 -42 -39
Biodegradability (28d), % OECD 301B 76 68

Delivering value across the industrial space

Download our white paper to find out more about how fire-resistant hydraulic fluids can bring value to your operations – driving performance, extending service life and helping you to meet your environmental responsibilities.

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Download the product sheet

Find out more how Shell Fire-Resistant Hydraulic Fluid S2 DU can protect your hydraulic systems in extreme conditions to drive productive operations

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1 Shell Fire Resistant S1 DU, S2 DU and S3 DU are biodegradable by greater than 60% after 28 days in the OECD 301B Carbon dioxide evolution test.