Conoco FR Hydraulic Fluid is an invert-emulsion (water-in-oil) type fire-resistant hydraulic fluid developed for use in hydraulic systems operating at 2000 to 3000 psi in areas subject to fire hazards. It combines the benefits of an oil-based hydraulic fluid with the fire-resistant properties of water. It is approved by the MSHA for use in underground mining equipment.

FR Hydraulic Fluid is formulated with high-quality paraffinic base oils, 40% water and a special emulsifier than produces a stable, homogeneous invert emulsion. It is fortified with antiwear additives, rust and corrosion inhibitors, and a biocide. The outer oil film lubricates and protects hydraulic system components against rust, corrosion and wear. The inner water core provides fire resistance in case of ignition of a fluid leak. The biocide helps prevent bacterial growth in system reservoirs.

FR Hydraulic Fluid is compatible with most hydraulic pump types, including vane, piston and gear pumps. It is safe to use with packing and seal materials commonly used in conventional oil systems. Avoid cork shaft seals and butyl seals and packing. Proper hydraulic system preparation is necessary when changing over from a conventional petroleum oil or water-glycol fluid.

Caution: FR Hydraulic Fluid should not be used in systems where operating temperatures exceed 175°F (79°C). This product contains water and should not be stored at temperatures over 130°F (54°C). Water content must be maintained at a minimum of 40% (by volume) to ensure adequate fire resistance.
Unit of Measure


ISO Grade

N/A 100

Density @ 15.6 ºC (60 ºF)

N/A 0.922 g/cm³7.68 lbs/gal
Color1 N/A Milky White

Freezing Point

N/A -34 ºC-29 ºF

Pour Point

N/A -29 ºC-20 ºF

Viscosity @ 40ºC

N/A 103 cSt

Viscosity @ 100ºC

N/A 18.5 cSt

Viscosity @ 100ºF

N/A 520 SUS

Viscosity @ 210ºF

N/A 94.0 SUS

Viscosity Index

N/A 200
Four-Ball Wear Scar Diameter2 N/A 0.55 mm

pH (neat)

N/A 9.4
Rust Test3 N/A Pass

Water Content Volume

N/A 40 %


N/A Hydraulic systems operating in areas subject to fire hazards, such as:

  • Underground mines
  • Steel mills, aluminum mills and foundries
  • Molding and metal die-casting machinery
  • Welding machines
  • Furnace charging equipment
  • Open hearth and basic oxygen furnace (B.O.F.) equipment
  • Power transmission plants
FR Hydraulic Fluid meets the performance requirements of :
  • Denison HF-3 Hydraulic Fluid - Invert Emulsions
  • Factory Mutual Group III Fluid
  • U.S. Steel 168, Inverted Emulsions



  • Fire resistant for safety
  • Excellent wear protection
  • Excellent rust and corrosion protection
  • Excellent emulsion stability
  • Compatible with seals and packing used in oil systems
  • Contains a biocide to resist bacterial growth
  • Fire resistance certified by Factory Mutual Research Corporation
  • MSHA approved (Approval Number 30-32-3)

Health and Safety Information

N/A For recommendations on safe handling and use of this product, please refer to the Material Safety Data Sheet via

Shipping Note

N/A Shipping will be quoted upon receipt of your order.

  • 1 Test-Visual
  • 2 ASTM D-4172
  • 3 ASTM D-665 A&B