This specification covers one
grade of petroleum base hydraulic fluid that is rust inhibited and used both as a
preservative for hydraulic systems and components as well as being an operational fluid. The hydraulic
fluid is identified by Military Symbol OHT and NATO Symbol C-635.
MIL-PRF-6083 Intended Use:
The hydraulic fluid is intended for
use as an operational fluid from -54°C
where corrosion protection is required and a determination has been made
that MIL-PRF-46170 Type I (FRH) hydraulic fluid cannot be used. This
includes use in recoil mechanisms and hydraulic systems for rotating weapons or aiming
devices of tactical and support ordnance equipment, except combat armored vehicles/equipment
which require FRH. The hydraulic fluid is also used as a preservative fluid for aircraft hydraulic
systems and components where MIL-H-5606 (OHA) or
MIL-PRF-87257 is used as an operational fluid.
MIL-PRF-6083 Cleaning agents
Isopropyl alcohol should not
be used as a cleaning agent on components containing any parts which may have come in
contact with hydraulic fluid. A sticky acrylic resin is formed which may be detrimental to the
proper operation of hydraulic components.
If isopropyl alcohol must be used as part of a cleaning
sequence, it is essential that the components be thoroughly dried to remove all traces of
should not be used for cleaning hydraulic components. Residual solvent contaminates the
hydraulic fluid and may cause corrosion
Recommended solvents. The recommended solvents
are P-D-680, type II, or other petroleum distillate type solvents.
Prior to use in the intended
equipment, the product may be stored under conditions of covered or uncovered storage
in geographic areas ranging in temperatures from -57°C to +49°C.
Owing to the difficulty of preventing contamination after the opening of
a container, it is recommended that the hydraulic fluid be purchased in
16-ounce (oz), 1-qt, and 1 gal containers by all users. If the fluid is
dispensed from larger containers, strict procedures must be employed to
exclude and remove moisture, solid particles or other contaminants.
Interchangeability and compatibility
fluids are not substitutable for (interchangeable with) any other fluids. MIL-PRF-6083
fluids should not be mixed (regarded as compatible) with any other fluids except those
conforming to MIL-PRF-87257,
MIL-PRF-46170 Type I, and
The product may contain 0.5 percent tricresyl phosphate, where not more than 0.01 percent may be present as the ortho
isomer. If this ortho isomer of tricresyl phosphate is absorbed through the skin or taken
internally it may cause paralysis. Accumulated waste liquids should have the exterior of the outer pack
marked as containing tricresyl phosphate to assist disposal facilities to manage the product
according to regulations promulgated by the US Environmental Protection Agency under Public Law
94580, Resource Conservation and Recovery Act of 1976.
Handling and safety precautions
handling the product should wear appropriate impervious clothing to prevent repeated or
prolonged skin contact. Local appraisal is required for exact health and safety implications and compliance with
OSHA regulations. Product labeling and Material Safety Data Sheets (MSDS)
information should be used by safety and health office of using activity to prescribe precise
application of protective measures. If skin or clothing becomes moistened with the product, personnel should
promptly wash with soap or mild detergent and water. Respirators are not required unless
there is an inhalation exposure to mists.
Personnel should wear protective clothing when using the
product and when cleaning up spills.
Depending on the size of
spills, paper towels or absorbent should be used to absorb the liquid. Contaminated soil
should be removed and placed in a box with absorbent or towels. This box with spill clean-up
wastes should either be buried along with ordinary refuse at a rate not to exceed 10 lbs of
clean-up waste per spill event or be incinerated in a permitted municipal waste incinerator. Bulk wastes and
contaminated liquids should not be landfilled. Partially full containers or contaminated
product should be collected centrally for commercial recycling by a commercial reprocessing firm.
Recycling by DoD military field activities, including depot-type operations, are not
authorized at this time. Liquid products used for heat recovery are regulated by the Environmental
Protection Agency under Public Law 94580, Resource Conservation and Recovery Act of 1976. Heat
recovery is required to meet the Standard in 40 CFR 266, subpart E, Used Oil, burned energy recovery.
Container Disposal Sonic shear test equipment. A 250 W, 10 KC magnetostrictive oscillator model
Tops from one-time-use
containers should be discarded with ordinary refuse. Containers should be made as empty as
possible using gravity draining, after which they should be crushed and buried in an authorized
sanitary landfill or incinerated with general refuse. No special decontamination procedures
are required for empty containers or their lids.
Recommended maximum blending temperature. At no
time during compounding process or any operations subsequent thereto, should the
temperature of any of the ingredients of the liquid, or the fluid itself, be greater than 149 °C.