No Detectable Oxidation Products After About 750 Hours
After approximately 750 hours of EFR D2 cleaning, analysis of a hydraulic elevator’s 23-year-old HLPD oil found no detectable oxidation products and only minimal particle contamination. The system contained 450 litres. Electrostatic cleaning was suitable in this case because most of the old oil’s D additives had already reacted.
Case Background
FRIESS’s former managing director, Mr Friess, was in contact with the property manager of an apartment building with a hydraulic elevator. After 23 years of oil use, the service company recommended analysis and replacement depending on the result.
Given the company’s quotation and lead time, Mr Friess analysed the oil himself using a FRIESS inspection kit. It contained substantial oxidation products and moderate particle contamination.
The Problem
The elevator used HLPD hydraulic oil. Unlike standard HLP oil, it contains additional detergent and dispersant additives that keep dirt and water suspended to protect the system. This oil type is often used in mobile hydraulics or systems exposed to strong temperature fluctuations, preventing water from settling and helping bind dirt particles for filtration.
The Solution: Electrostatic Hydraulic Oil Filtration
These additives usually increase the oil’s electrical conductivity. Fresh HLPD oils are therefore often unsuitable for FRIESS electrostatic oil cleaning systems, which require an electrically insulating fluid.
After 23 years in service, much of the detergent additive had already reacted, so a FRIESS EFR system could be used. An EFR D2 electrostatic oil cleaner was moved into the basement and connected to the elevator’s 450-litre hydraulic system.
Results
After approximately 750 hours of cleaning, a new oil analysis showed a major improvement:
- No oxidation products were detected
- Only minimal particle contamination remained
With the now-clean “new” old oil, the elevator can hopefully operate for another 23 years using the same oil charge. This was the best solution environmentally and economically, and was completed well before the usual lead time for an elevator maintenance appointment.
Dark hydraulic elevator oil, valve-block failures or more frequent maintenance?
Please share your hydraulic oil grade, reservoir volume, system pressure, contamination class, particle and oxidation-product conditions, existing filtration method and target cleanliness. Our China engineering team can recommend an EFR D2 electrostatic oil cleaner configuration, bypass flow rate and operating schedule for your conditions.