Which hydraulic oil

The fluid typically used in these instances is vegetable oil. For applications in which hot surfaces or open flames are present, fire resistant oils should be used. Fire resistant fluids range from polyol esters biodegradable, miscible with oils to phosphate esters very high flash point, very caustic, very expensive to water glycol a mixture that must be monitored for proper content.

In situations where low temperature applications are present, the most commonly used oil is automatic transmission fluid ATS , as it has a very low pour point. For more information on hydraulic fluids or for help selecting the proper fluid for your environment, please comment below or use our contact form to request additional information.

For low-temperature applications, automatic transmission fluid ATS is often used, as it has a very low pour point. The fluids that you should use largely depend on the environment of your application. For mobile hydraulic equipment users, this translates to reduced fuel consumption. When to Use a Monograde Hydraulic Oil If the hydraulic system has a narrow operating temperature range and it is possible to maintain optimum fluid viscosity using a monograde oil, it is recommended not to use a multigrade for the reasons stated above.

About the Author Brendan Casey. Brendan Casey has more than 20 years experience in the maintenance, repair and overhaul of mobile and industrial equipment. For more information on reducing the operating cost and increasing the Read More.

Related Articles. Understanding Logic Valves in Hydraulic Systems. Featured Videos. Atten2 S Oil Wear 2. Featured Whitepapers. Does water ingress have to be the end of your oil's life? Neural Network Detection of Machine Faults. Cement Industry Contamination Solutions. In addition, they provide ecological compatibility and can be used for stationary and mobile applications in industrial, forestry, mining, tunnel building, and earthmoving equipment.

In recent years, biodegradable hydraulic oils like Valvoline Ultramax Bio premium synthetic hydraulic fluid have been replacing mineral oil-based hydraulic lubricants. Additionally, they can be divided into several groups including:. Due to their features, biodegradable hydraulic oils are also used for marine applications and hydraulic systems of boats and ships. This category is based on numerous international guidelines which regulate which base oils and additives can be used in the formulation of these hydraulic fluids.

Food-grade hydraulic oils have subgroups which indicate whether the lubricant is suitable for use in the food industry where no direct contact with the food can happen and the subgroup where such contact might occur.

The base oils used for these hydraulic lubricants are special white oils , special polyalphaolefin grades , and special polyglycols. These oils are used in the hydraulic systems in aviation and can handle high pressures and extreme climatic conditions with drastic temperature changes. Therefore, these fluids have to be exceptionally thermally stable and have a high viscosity index. Also, they have to be fire-resistant and must be free from contaminants. The lubricating property of hydraulic oils is achieved through the addition of additives.

Additionally, these systems of additives or additive packages, additive mixtures, or add packs as they are also known, have different properties with different functions. The creation of an additive package is a very delicate process as additives need to be compatible and complement each other. Some of the properties of base hydraulic oils that can be improved are stability, anti-corrosion, anti-wear, viscosity-temperature stability, foaming, detergency, water separation, and friction coefficient , to name the most important ones.

An additional classification that is based on the system of additives used in the formula of the hydraulic oil is as follows:. As we can see from the aforementioned categorization, hydraulic oils have to possess certain properties to be able to meet the requirements of the hydraulic systems and operating conditions.

Whether it is heavy-duty or an application which does not have such extreme working conditions, hydraulic oil needs to be:. Additionally, the choice of hydraulic fluids has to be cost-effective for the owner of the hydraulic machinery or equipment.

A single hydraulic oil cannot usually meet all the aforementioned points. That is why hydraulic oils are specially formulated based on the conditions in which they will be applied.

The viscosity of hydraulic oils is its highly important feature as it represents its resistance to fluctuations in temperatures. Selecting the best product for your system requires that you collect and utilize all available information. Hydraulic fluid has many roles in the smooth operation of a well-balanced and designed system. These roles range from a heat transfer medium, a power transfer medium and a lubrication medium.

The chemical makeup of a hydraulic fluid can take many forms when selecting it for specific applications. It can range from full synthetic to handle drastic temperature and pressure swings to water-based fluids used in applications where there is a risk of fire. A synthetic fluid is a manmade chain of molecules that are precisely arranged to provide excellent fluid stability, lubricity and other performance-enhancing characteristics. There are some disadvantages to these fluids, including high cost, toxicity and potential incompatibility with certain seal materials.

A petroleum mineral fluid is a more common fluid and is made from refining crude to a desired level to achieve better lubricant performance with the inclusion of additives, which range from anti-wear AW , rust and oxidation inhibitors RO and viscosity index VI improvers.

These fluids offer a lower-cost alternative to synthetics and can be very comparable in performance when certain additive packages are included. Water-based fluids are the least common of the fluid types. These fluids are typically needed where there is a high probability of fire. They are more expensive than petroleum but less expensive than synthetics.

While they offer good protection from fire, they do lack on wear protection abilities. There are three major design types of pumps used in hydraulic systems: vane, piston and gear internal and external , and each of these pump designs are deployed for certain performance tasks and operations.