Hydraulic fluid is a substance that transfers power and heat in hydraulic systems, such as brakes, steering, lifts, and presses. Hydraulic fluid can also act as a lubricant, coolant, and sealant in hydraulic equipment. There are many types of hydraulic fluid, but they can be classified into three main categories based on their base oil type: mineral, synthetic, and vegetable.
Mineral-based hydraulic fluid is the most common type of hydraulic fluid. It is derived from the distillation of crude petroleum oil, which removes harmful contaminants and hydrocarbons. Mineral-based hydraulic fluid can be further divided into three subcategories: solvent-refined, hydrocracked, and hydrotreated. Solvent-refined mineral fluid is the oldest and cheapest type, but it has poor thermal stability and anti-wear properties. Hydrocracked and hydrotreated mineral fluids have less sulfur impurities and higher viscosity index, which means they can maintain their viscosity over a wider temperature range. Mineral-based hydraulic fluid is suitable for various industries, such as mining, construction, and forestry, where cost-effectiveness and durability are important. However, mineral-based hydraulic fluid is not very biodegradable and can cause environmental problems if spilled or leaked.
Synthetic-based hydraulic fluid is a type of hydraulic fluid that is artificially manufactured from chemical compounds, such as esters, polyglycols, and silicones. Synthetic-based hydraulic fluid has many advantages over mineral-based hydraulic fluid, such as better fire resistance, corrosion resistance, oxidation resistance, and lubricity. Synthetic-based hydraulic fluid can also operate at higher and lower temperatures than mineral-based hydraulic fluid, which makes it ideal for aerospace, marine, and military applications. However, synthetic-based hydraulic fluid is more expensive and less compatible with other types of hydraulic fluid, which may require special seals and filters to prevent leakage and contamination.
Vegetable-based hydraulic fluid is a type of hydraulic fluid that is made from natural oils, such as rapeseed, sunflower, soybean, and palm. Vegetable-based hydraulic fluid is the most environmentally friendly type of hydraulic fluid, as it is biodegradable, renewable, and non-toxic. Vegetable-based hydraulic fluid can also reduce friction and wear, extend the life of hydraulic components, and lower the operating temperature of hydraulic systems. However, vegetable-based hydraulic fluid has some drawbacks, such as lower oxidative stability, higher water absorption, and lower cold flow properties than mineral-based and synthetic-based hydraulic fluids. Vegetable-based hydraulic fluid is suitable for agricultural, food processing, and outdoor applications, where environmental safety and cleanliness are important.
In conclusion, hydraulic fluid is a vital component of hydraulic systems, and it can be classified into three main types based on its base oil type: mineral, synthetic, and vegetable. Each type of hydraulic fluid has its own advantages and disadvantages, depending on the application and performance requirements. Therefore, it is important to choose the right type of hydraulic fluid for the specific hydraulic system, and to follow the manufacturer’s recommendations and maintenance guidelines to ensure the optimal functioning and safety of the hydraulic equipment.
