ASTM Approves New Standard for Varnish Potential Testing

Noria news wires
Tags: varnish

ASTM International recently approved a new standard for testing the varnish potential of in-service lubricants: ASTM D7843 - Standard Test Method for Measurement of Lubricant Generated Insoluble Color Bodies in In-Service Turbine Oils using Membrane Patch Colorimetry (MPC).

"Varnish has plagued turbine oil users in recent years," said Dr. David Wooton, chairman of the ASTM work group that developed the new standard. "The new MPC test standardizes a powerful predictive tool for turbine and compressor users, allowing them to be aware of impending varnish problems."

Although MPC testing has already been globally adopted as the most common methodology for testing the varnish potential of turbine oils and other non-detergent lubricants, the new standard will increase testing consistency and precision. Improvements in test reproducibility are expected, as not all commercial labs are performing the test in the same manner.

"We view the MPC test as a powerful complement to our RULER technology," said Greg Livingstone of Fluitec, which helped develop the industry's first varnish potential test in 2005 and has been a supporter of the MPC test for years. "Trending antioxidant health and soft contaminant formation are critical to understanding the remaining useful life of your lubricants."

For more information on ASTM D7843, visit