Educating on Turbine Oil Microbial Contamination


Educating on Turbine Oil Microbial Contamination
Large hydro turbines spin to create electricity in the powerplant at Hoover Dam, located at the Black Canyon of the Colorado River, on the border between Nevada and Arizona. © CrackerClips Stock Media

A new ASTM international standard provides explanations of microbial contamination and biodeterioration and suggests methods to detect and control such conditions in turbine oils and turbine oil systems.

ASTM’s committee on petroleum products, liquid fuels and lubricants developed the standard, titled, “Standard Guide for Microbial Contamination and Biodeterioration in Turbine Oils and Turbine Oil System,” which will soon be published as D8506.

According to the guide’s scope statement, it will aim to help personnel who have a limited microbiological background better understand the symptoms, occurrences and consequences of chronic microbial contamination. The guide statement notes that steam turbines, and to a greater extent hydro turbines, are continuously exposed to water ingression, and that diligence is necessary to ensure seals and bearings remain in good condition to prevent that ingression or conditions conductive to biodeterioration. “However, due to the risk of the accumulation of condensation, all equipment can become susceptible when shutdown for extended periods,” the scope statement notes.

“Turbine oils are nominally water-free, and microbes are only metabolically active where traces of water accumulate in recirculating turbine oil systems,” ASTM member Fred Passman, president of Biodeterioration Control Associations Inc., explained in an ASTM press release. “Because of this, personnel responsible for power generation facility oil systems are generally unaware of the damage the microbes can cause to both the recirculating oil and the turbine oil system.”

He noted that, “symptoms ranging from decreased filter life to out-of-specification oil can reflect damage from uncontrolled microbial contamination.”

Passman said the new standard should prove useful to turbine oil suppliers, engineers responsible for power generator oil systems and operator chemists for turbine oil condition monitoring.

Another benefit is to support sustainability, including the drive for affordable and clean energy. “Maintaining and extending turbine oil functional life translated into increased power generation efficiency – in turn, contributing to power generation affordability,” he said. “Failed turbine oil must be rerefined or sent to waste treatment. Consequently, by reducing the risk of uncontrolled microbial contamination in turbine oils, D8506 contributes to clean energy by reducing the waste stream.”

Drafted by Passman in 2010, the new D8506 guide was balloted for the first time in 2013 and after four additional rounds of balloting, obtained ASTM approval this year, he told Lube Report.