Types Of Hydraulic Fluids (Type 1)

Water And Water Based Fluids

• Water

It is least expensive hydraulic fluids.It is treated with some chemicals before used in a fluid power system.

1. Advantages
   1) Inexpensive
   2) Readily available
   3) Fire resistance

1. Disadvantages
   1) No lubricity
   2) 

Corrosive

• Water Based Fluids

Under this classification,mainly there are two types

1) Water Glycol

2) Water oil 

emulsions

1. Water Glycoles
   In water glycol combination,35-60% water to provide the fire resistance,plus a glycol anti frees like ethylene, ethylene,propelene which is non-toxic and bio-degradable.and it provide more viscosity.the operating temperature for water glycol fluids should be maintained below 50 degree Celsius to prevent evaporation and deterioration of the fluid.
   Viscosity,PH,water hardness monitoring are very important in water glycol systems.
   Advantages
   Good fire resistance,inexpensive.
   Disadvantages
   -Not good for high loads
   -Poor corrosion resistance.
2. Water Oil Emulsions
   -Oil in water
   In this emulsion very small oil droplets dispersed in a continues water phase.these fluids have low viscosity, excellent fire resistant and good cooling capacity and some additives are used to improve lubricity and to protect against rest.
   -Water in oil
   In thisemultion,water is approximately 40%the major condunt is oil.In this combination very small water droplets dispersed in a continues phase of oil.
   The oil phase provides good to exellent lubricity  while the water condent provides the cooling capability and fire resistance.
   Advantages
   -Good for fire resistance
   -Inexpensive
   Disadvantages
   It should be properly monitored to ensure that the proper viscosity is maintained.