Hydraulic oils are liquids used to transfer forces in hydraulic systems. They are an integral part of modern machinery in the construction, manufacturing, automotive, and agricultural industries. The properties of the oil are directly related to its ability to safely and reliably operate under a wide range of temperatures, pressures, speeds, and environments.
Hydraulic oil is composed of refined mineral oil or synthetic base stocks, and contains additives to provide benefits such as corrosion inhibitor, anti-wear glands and friction modifiers. Generally, fluids used in hydraulic systems are formulated to provide superior lubrication and protect against oxidation and corrosion.
Selecting the best hydraulic oil for the system depends on a number of factors, such as type of application, type of material, temperature ranges, and flow capacity of the device. It is important to match the right viscosity oil to the application and environmental conditions. Viscometer provides a numeric value which is called the viscosity index (VI). A higher VI means that the oil has better resistance to shear stress, making it more efficient and stable over time.
There are two primary types of hydraulic oils – mineral and synthetic. Mineral oils are derived from petroleum products and form the basis for most automotive applications. Synthetic oils are engineered and aim to improve performance in applications where temperatures and pressures are extreme and prolonged.
Mineral hydraulic oils include monograde, multigrade, and fire-resistant fluids. Monograde hydraulic oils are single-grade oils and tend to be the least expensive. Multigrade hydraulic oils combine two or more viscosities and are designed to reduce deposits, foam, and wear. Fire-resistant hydraulic oils are commonly used in hazardous areas where the risk of fire or explosion is present.
Synthetic hydraulic oils are usually found in high-pressure, temperature, or load applications. These fluids are formulated to work with components that require higher protection, such as radial and thrust bearings, as well as seals, hoses, and other surfaces prone to abrasion and erosion.
Hydraulic oils provide a range of benefits for machinery and equipment. They help ensure that friction is reduced between moving parts, reduce the risk of wear, improve lubrication, and help prevent corrosion and oxidation. In addition, they help maintain temperatures and contribute to excellent cold weather performance.
Hydraulic oils also promote longer equipment life by protecting components from rust, dust, and dirt, and providing excellent oxidation and thermal stability. They are also specially formulated to provide good detergency and dispersancy, which helps reduce deposits and sludge buildup.
Using a hydraulic oil that is designed for the application can help prevent breakdowns, improve reliability, and extend the life of the system. It is important to select a hydraulic oil grade that meets the manufacturer’s requirements and is suitable for the environment in which it is used.