Hydraulic press Machine effect used not only to pass the working medium pressure. Working parts of the machine and ensure work is sensitive, reliable, long life and low leakage. The basic requirements for Hydraulic press Machine working medium:
1.have appropriate liquidity and low compressibility, in order to improve transmission efficiency.
2.can prevent corrosion
3.have good lubricating properties
4.easy to seal
5.stable performance. Long-term work without deterioration.

Hydraulic press Machine initial water as the working medium. After switching to the water by adding a small amount of emulsified oil emulsion formed. In order to increase lubricity and to reduce corrosion. The latter appeared to mineral oil as the working medium of the hydraulic machine of the 19th century. Oil has good lubricity, corrosion resistance, and a moderate viscosity. Conducive to improving the performance of hydraulic machines. Half of the emergence of a new type of water-based emulsion of the 20th century. Emulsified form is the "water in oil." Instead of the original "oil in water." Foreign "oil-water" emulsion an oil. It lubricity and anti-corrosion properties close to oil. And a little oil content, not combustion. But the water-based emulsion expensive. Limited its promotion.