Choose the best hydraulic oil to reduce downtime and costs.

Most people choose the best hydraulic oil based solely on the manufacturers specifications. While this is very important (And during the warranty period, it’s vital) the correct selection of hydraulic oils entails much more.

Hydraulic systems have become extremely sophisticated over the past few years. Speed and pressure have increased tremendously. A few years ago, hydraulic pressures of 30 to 70 Bar, or even 100 Bar were common. Today, pressures are as high as 700 Bar in certain
applications.

As a result of these increased pressures, wear rates have gone up dramatically, particularly in vane-type pumps. Specific anti-wear additives are now required. Higher speeds and pressures have caused considerable increases in the bulk oil temperature. Oxidation of the hydraulic oil cannot be tolerated. So when choosing the best hydraulic oil, it should have extreme high-temperature oxidation resistance, such as offered by quality synthetic hydraulic fluids. Protection against foaming, rust and wear is also absolutely necessary.

What are the factors to be aware of when you choose the best hydraulic oil.

To a large extent the quality of the lubricant is determined by the base stock. These base oil stocks must then be blended with precisely the amount of selected additives to supplement and improve the qualities being built into the hydraulic oil.

Because of increased operating temperatures, the viscosity stability is extremely important when you choose the best hydraulic oil. At higher temperatures, the oil tends to become thinner (Reduced viscosity). As the viscosity decreases, leakage and slip could increase. External leakage means loss of fluid through seals; internal leakage or slip means reduced efficiency of the system.

At colder temperatures the oil becomes more viscous, and at extremely low temperatures the viscosity can rise until it begins to limit the flow into the pump. When the viscosity reaches a point where the fluid cannot fill the displacement volume of the pump in the time allowed at normal operating speed, the pump will begin to cavitate. As the viscosity continues to rise, the degree of cavitation increases. Prolonged cavitation can be destructive. The noise level would increase and the efficiency would drop off rapidly. Cavitation can also be caused by restrictions in the inlet line to the pump. So it’s extremely important that when you choose the best hydraulic oil you ensure the viscosity is correct for the operating environment.

There are two good yardsticks for determining the suitability of any given oil:

• Oil Specifications 
• Performance Data 
• Regular oil analysis

Specifications are used to select the correct oil with respect to viscosity
VI (Viscosity Index), and other characteristics that can be determined in the laboratory and which have a bearing on the ability of the oil to perform satisfactorily.

However to choose the best hydraulic oil the performance data must be used as a guide in making the ultimate choice of an oil to give you (1) efficient power transmission, (2) proper lubrication, (3) long oil life, (4) wear protection for long equipment life.

By implementing an oil analysis regime you will be able to validate your choice of fluid as well as monitor both your equipments condition as well as the condition of the hydraulic oil.

Tips to remember when you choose the best hydraulic oil.

• Highest consideration must be given to characteristics that have to do with performance. Reduction in wear, viscosity, VI and oxidation, rust and corrosion resistance can be checked in the laboratory, but actual performance gives a better indication of what the oil can do. 
• Viscosity is an important specification. For proper efficiency, when you choose the best hydraulic oil the viscosity should be stable under the required operating temperature. Viscosity recommendations are available from the equipment manufacturer, but when in doubt consider using synthetic hydraulic lubricants for their VI stability and resistance to oxidation. 
• Oxidation occurs in any hydraulic system and can be controlled. Oxidation rates increase with temperature and percentage of contaminants. The greater the oxidation resistance of the oil, the better the protection. 
• Rust can cause serious damage to any hydraulic system. Therefore it’s important that the hydraulic fluid contains corrosion inhibitors. 

Because of the value of the equipment and the financial losses incurred due to breakdowns, if you choose the best hydraulic oil it will more than pay for itself in the long run. Quality oils, such as synthetic fluids, will always have the proper viscosity, VI, pour point, oxidation stability, rust prevention, foam resistance, water separation characteristics and anti-wear properties. Use of such oils results in reduced wear, reduced downtime and reduced labour. In fact, they more than offset the initially higher cost.

Habot Synthetic Lubricants will help you choose the best hydraulic oil from our quality range of lubricants. Give us a call or send us an Email, and we’ll be happy to give you our professional advice on which of our products is the right oil for your needs.