Renewable Lubricants Develops Biodegradable Hydraulic Fluids for Cold Temperatures

Renewable Lubricants has developed the Bio-Ultimax 1200LT Hydraulic Fluids to provide an environmentally friendly option capable of working in low-temperature conditions.

Key features of the Bio-Ultimax 1200LT Hydraulic Fluids include:

• cold temperature pumpability down to -40 C (-40 F) and pour point as low as -60 C (-76 F)
• oxidation resistance and anti-wear properties
• enhanced seal conditioning properties reduce oil leakage and extend seal life
• ability to be used in both high- and low-pressure systems
• meeting EPA guidelines for Environmentally Acceptable Lubricants (EALs).

Formulating a High-Performance Biodegradable Hydraulic Fluid

The Bio-Ultimax 1200LT Hydraulic Fluids are made from a fully synthetic biodegradable formula, said Ben Garmier, Vice President of Renewable Lubricants, in an interview with Power & Motion.

While many companies use natural ester base oils for their biodegradable hydraulic fluids, Renewable Lubricants has chosen to use synthetic esters for its base oils. Garmier said many find natural ester-based fluids do not perform as well because they are made from vegetable oils. This can make it difficult for them to be used in applications that may experience extreme temperature fluctuations.

Synthetic esters are known for their oxidation stability which helps to prolong fluid effectiveness and reduced maintenance. These esters have a lower pour point as well, benefiting use of the hydraulic fluids in colder environments. The Bio-Ultimax 1200LT Hydraulic Fluids have a pour point as low as -60 C (-76 F); pour point is a laboratory test conducted to determine at what temperature a hydraulic fluid will get cold and freeze.

When developing a biodegradable hydraulic fluid, no matter the weather conditions it will be used in, there are several performance factors that need to be taken into account when selecting the base oils and additives that will be used.  

Garmier noted that many synthetic base oils do not play well with the seals used in a hydraulic system. The oils will sometimes dry the seals out, causing them to crack and leak. Other variants can be absorbed by rubber seals which makes them expand and eventually blow the seal out of the hydraulic system.  

Therefore, it’s important to strike the right balance when choosing a base oil “to make sure that you're not drying the seals out too much and you're also not causing too much expansion,” he said. “We've got a good balance in [the Bio-Ultimax 1200LT] of seal conditioning that keeps those seals nice and pliable but doesn't allow them to dry out and also doesn't allow them to become overly absorbed into the seal.”

Garmier said that some of the other cold temperature hydraulic fluids in the market require more caution with the types of seals used in a hydraulic system but the Bio-Ultimax 1200LT works with the majority of the major hydraulic seal types currently utilized.

View the content below for more on biodegradable hydraulic fluids.

Another benefit Garmier pointed to is the Bio-Ultimax 1200LT’s high flash point. He said other cold temperature hydraulic fluids that are not biodegradable are typically very caustic and thinner which helps prevent them from freezing. However, they can have issues with flammability because of this.

Bio-Ultimax 1200LT, on the other hand, has flash and fire safety features built into it to prevent the flammability issues cold temperature petroleum-based hydraulic fluids face.

Inclusion of various hydraulic additives aid with other performance characteristics as well such as offering anti-wear properties, extreme pressure chemistry and demulsifiers — chemicals to separate emulsions such as water in oil. This helps to ensure the hydraulic fluids not only meet environmental requirements but those of OEMs as well.