Lubricating hydraulic fluid 31

for aircraft

Product summary
AeroShell Fluid 31 is a synthetic hydrocarbon aircraft hydraulic fluid with improved fire resistance, high flash point and good oxidation and thermal stability.

Features and benefits

• Enhanced fire resistance – formulated with improved fire‑resistant properties to reduce fire risk in high‑temperature conditions.
• High oxidation stability and corrosion resistance – resists thermal degradation and protects hydraulic components, extending fluid life.
• Low‑temperature fluidity – maintains flow and responsive operation at low temperatures.
• Anti‑wear protection – additives protect pumps, valves and actuators against wear.
• Wide operating temperature range – functional from -40°C to +205°C (-40°F to +401°F).

Specifications & approvals

• United States: MIL‑PRF‑83282D
• France: DCSEA 437/B
• NATO code: H‑537
• Joint Service Designation: OX‑19

Applications
AeroShell Fluid 31 is recommended for aircraft, ordnance and missile systems and associated hydraulic and servo systems using synthetic elastomer seals. Typical uses include autopilots, shock absorbers, brakes, flight control systems and hydraulic servo‑controlled systems. It is also approved for certain turbine cooling applications (cabin air compressors). The fluid is suitable as a fire‑resistant alternative to mineral hydraulic oils in systems requiring improved fire performance.
AeroShell Fluid 31 is compatible with AeroShell Fluids 41 and 61 and can be used in systems designed for MIL‑PRF‑5606, MIL‑PRF‑6083, MIL‑PRF‑87257 and MIL‑PRF‑46170. It is a synthetic hydrocarbon and should not be used with incompatible seal materials. Avoid chlorinated solvents for cleaning components as residues can cause corrosion.

Health, safety and environment
Health and Safety

• When used as recommended and with good hygiene, this product is unlikely to present significant health or safety hazards.
• Avoid skin contact. Use impervious gloves when handling used oil. After skin contact wash immediately with soap and water.
• Consult the Safety Data Sheet (SDS) for detailed health and safety guidance.

Protect the Environment

• Collect used oil and deliver to an authorised recycling or disposal facility. Do not discharge into drains, soil or water.

Additional information

• For application advice not covered here contact your local Shell representative or technical support.

Typical physical characteristics
Typical characteristics are available as a reference and may vary with production.

Technical specifications

• Model: AeroShell Fluid 31
• Type: Synthetic hydrocarbon aircraft hydraulic fluid
• Key properties: Enhanced fire resistance, high flash point, oxidation and thermal stability, low‑temperature fluidity, anti‑wear protection, wide operating temperature range
• Approvals: MIL‑PRF‑83282D; DCSEA 437/B; NATO H‑537; Joint Service Designation OX‑19
• Operating temperature range: -40°C to +205°C (-40°F to +401°F)
• Compatibility: Compatible with AeroShell Fluids 41 and 61; suitable for systems designed for MIL‑PRF‑5606, MIL‑PRF‑6083, MIL‑PRF‑87257 and MIL‑PRF‑46170
• Notes: Not suitable for contact with incompatible seal materials; avoid chlorinated solvents for cleaning.