Hydraulic oils, often referred to as hydraulic fluids or hydraulic oil fluids, are specially formulated oils used in hydraulic systems to transmit power, lubricate components, and maintain the proper functioning of various machinery and equipment. These systems are commonly found in construction equipment, industrial machinery, agricultural machinery, and automotive applications.

Hydraulic fluid comes in various types, each with its own set of characteristics and applications.

Here are some common types of hydraulic fluids:

• Mineral Oil:

  This is the most common type of hydraulic fluid. It is based on refined crude oil and is suitable for general hydraulic applications. It provides good lubrication and heat transfer properties.

• Biodegradable Hydraulic Fluid:

  These fluids are formulated to be environmentally friendly and are often used in applications where there is a risk of spills or leaks into the environment. They can be vegetable oil-based or synthetic.

• Synthetic Hydraulic Fluid:

  These fluids are engineered for specific applications and can offer superior performance in terms of temperature stability, shear resistance, and overall efficiency. Common synthetic hydraulic fluids include polyalphaolefin (PAO), diester, and polyglycol.

• Fire-Resistant Hydraulic Fluid:

  These fluids are designed to be less flammable or even non-flammable to reduce the risk of fire in hydraulic systems. Types of fire-resistant hydraulic fluids include water-based (HFA and HFB), oil-in-water emulsions (HFC), and synthetic fluids (HFD).

• Highly Viscous Hydraulic Fluid:

  These fluids have high viscosity and are used in applications where heavy loads and slow movements are common. They provide excellent lubrication and cushioning.

• Low Viscosity Hydraulic Fluid:

  These fluids are used in systems where fast response times and low energy consumption are important. They are often used in precision equipment.

• Phosphate Ester Hydraulic Fluid:

  These fluids are known for their fire resistance and are used in specialized applications such as aviation and aerospace.

• Silicone Hydraulic Fluid:

  Silicone-based hydraulic fluids are often used in extreme temperature environments because of their wide operating temperature range. They are also resistant to oxidation and have good dielectric properties.

• Vegetable Oil Hydraulic Fluid:

  Made from natural oils, such as soybean or rapeseed oil, these biodegradable fluids are often used in environmentally sensitive areas.

• Water-Glycol Hydraulic Fluid:

  This is a fire-resistant hydraulic fluid commonly used in applications where fire hazards are a concern. It consists of a mixture of water and glycol.

Hydraulic oils come in various grades, and their specifications are defined by organizations like the International Standards Organization (ISO), American Gear Manufacturer’s Association, leading gear oil standards (AGMA) and the Society of Automotive Engineers (SAE).

Here is a list of common hydraulic oil grades:

• ISO 32:

  This hydraulic oil grade is thin and suitable for systems operating in cold conditions or with very fine clearances.

• ISO 46:

  This is a medium-weight hydraulic oil suitable for a wide range of applications, including general hydraulic systems and mobile equipment.

• ISO 68:

  A heavier hydraulic oil, often used in applications where higher temperatures or heavier loads are encountered.

• ISO 100:

  This hydraulic oil grade is used in systems where higher viscosity is required, typically for high-pressure hydraulic systems.

• ISO 150:

  A thicker hydraulic oil grade used in heavy-duty applications, such as industrial machinery and certain types of construction equipment.

• ISO 220:

  A heavy hydraulic oil grade suitable for systems with high loads or extreme operating conditions.

• ISO 320:

  An even thicker hydraulic oil used in heavy industrial equipment and hydraulic systems that require high viscosity.

• ISO 460:

  This hydraulic oil grade is among the heaviest and is used in heavy-duty industrial applications and large hydraulic equipment.

• SAE 10W:

  This grade is specified by the Society of Automotive Engineers and is commonly used in mobile hydraulic systems, especially in colder climates.

• SAE 20W:

  Similar to SAE 10W but slightly thicker, suitable for mobile and industrial applications.

• SAE 30:

  A heavier SAE grade used in hydraulic systems operating in warmer conditions and with heavier loads.

• SAE 40:

  A thicker SAE grade suitable for high-temperature hydraulic systems and those with very heavy loads.

Applications

• Heavy Machinery
• Industrial Machinery
• Agricultural Equipment
• Automotive Systems
• Aviation
• Marine Industry
• Mining Equipment
• Oil and Gas Industry