What type hydraulic fluid to use

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. Each pump type must be treated on a case-by-case basis for lubricant selection. Vane: The design of a vane pump is exactly what its name depicts.

Inside the pump, there are rotors with slots mounted to a shaft that is spinning eccentrically to a cam ring. As the rotors and vanes spin within the ring, the vanes become worn due to the internal contact between the two contacting surfaces. For this reason, these pumps are typically more expensive to maintain, but they are very good at maintaining steady flow.

Vane pumps typically require a viscosity range of 14 to centistokes cSt at operating temperatures. Piston: Piston pumps are your typical middle-of-the-road hydraulic pump, and are more durable in design and operation than a vane pump; they can produce much higher operating pressures, up to 6, psi. Furthermore, they are refined to a level at which they achieve adequate lubrication properties. Then they are enhanced with a system of additives. These additives serve different functions and can have anti-wear properties, rust and oxidation inhibition properties, viscosity index improvement properties, and others.

Since they are petroleum-based, they represent a lower-cost option compared to their synthetic counterparts. Depending on the quality of the base oil and additive package, these mineral lubricating hydraulic oils can offer high performance like the Valvoline HVLP and HLP conventional hydraulic oils. The types of additives found in mineral-based hydraulic oils protect the hydraulic systems against corrosion, wear, water contamination.

Also, they improve the demulsifying properties of the oil and the viscosity index which improves their resistance to temperature changes. Synthetic-based hydraulic oil was designed to compensate for the shortcomings of mineral hydraulic oil. They are made of chemically-produced base oils which accounts for their superior performance compared to mineral hydraulic oils. What is more, they have proven performance at high temperatures, excellent oxidation stability, and biodegradability.

However, as synthetic fluids, they come at a much higher cost , can be highly toxic, and potentially incompatible with some seal materials. Both mineral and synthetic base oils are used in the formulation of fire-resistant hydraulic oils that biodegrade at very quick rates.

As the name implies, these hydraulic oil types are intended for applications with a high probability of fire including aviation, mining, steel mill, and die-casting applications. Thanks to this important feature, they are used in a range of applications and are less expensive than synthetic hydraulic oils. However, when it comes to their anti-wear protective properties, they are behind the synthesized fluids.

On the other hand, the system of additives used in fire-resistant hydraulic oils improves corrosion protection, reduces friction, and foaming. Fire-resistant hydraulic oil can be mineral oil-based oil-in-water emulsions , synthetic water-based solutions , mineral oil-based water-in-oil emulsions , water-based , and water-free. This category of hydraulic oils was developed with the rising standards with regard to environmental protection.

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:. An important issue to always keep in mind when selecting hydraulic oils for your applications is that viscosity varies with temperature.

Therefore, viscosity needs to be high enough to provide lubrication to your system, yet low enough as to not cause excessive pressure losses or problems drawing sufficient fluids through the pump cavitation. So, how do you determine the correct temperature to operate your hydraulic system? If you can place your hand on the reservoir and feel heat, yet comfortably keep you hand there, your hydraulic system is operating at a good temperature.

This trick works for almost any hydraulic system. Hydraulic fluids have also been developed for special circumstances that require special attention:. Food grade oils were developed for applications in which there is a possibility that fluid can contaminate consumable goods. Often these conditions will have influence on the hydraulic fluid type. Ask Suggest a topic. Related Posts. General Industry Henry is the answer for the highest demanding hydraulics 14 June Read article.

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