Removing Acids from Phosphate Ester Fluids
The total acid number (TAN) is a measurement of acidity that is determined by the amount of potassium hydroxide in milligrams that is needed to neutralize the acids in one gram of oil.
The TAN value in lubricant indicates the oxidation level and the subsequent corrosion risk to machinery.
The acidification of phosphate ester fluids causes:
- Increased corrosion in the system
- Lower fluid viscosity that puts critical components like servo valves and cylinders at risk of rapid surface degradation
- Sluggish response of control systems from stiction and oxidation by-products build ups
- Acids accelerate fluid degradation resulting in short service life of the fluid.
Lowering the acid content of the fluid is a critical step in fluid remediation and preventative maintenance. Treatment with the Pall Sentry fluid treatment system brings the fluid back to its OEM specified acid level for proper operation and extended fluid life. The unit does not release byproducts typically found in traditional acid removal systems, such as water from wet resins or sludge from Fullers earth and activated alumina systems.
Efficiency and Ease of Use
Tests have shown that synthetic fluids are perfect candidates for acid removal through resins. Acid levels in the fluid can be lowered below OEM specified limits by recirculating it through the Pall Sentry fluid treatment system.
The stand alone system is equipped with a specially formulated resin, in a semi dry package. The skid uses 3 resin bags stacked in the vessel. They can easily be changed and disposed of. Each set of resin bags will typically treat 500 gallons of acidic phosphate ester and bring the TAN level down to below 0.11.
The Pall Sentry fluid treatment system is connected to the main oil reservoir and circulates the oil at a rate of up to 5 gpm through the acid reduction unit and a high efficiency latest generation Pall Ultipleat® SRT filter. With each pass through the system, acid compounds are captured on the resin and the fluid is returned to the reservoir. Once used, the resin bags can be easily replaced and disposed of.