- Vessel owner/operators and equipment manufacturers must understand ester oil performance characteristics to assist in their selection of environmentally acceptable lubricants (EALs) in response to the new Vessel General Permit (VGP).
- In the marine environment, ester-based oils exhibit excellent biodegradation, non-bioaccumulation and low-toxicity characteristics. Operationally, they handle a wide range of temperatures, exhibit high viscosity, lubricity, corrosion protection and oxidative stability
When the Environmental Protection Agency (EPA) issued the new Vessel General Permit (VGP) in December 2013, lubricant and fluid manufacturers were prepared to give vessel owners a number of environmentally acceptable lubricants (EAL) to work with. EAL usage is now essentially required for any application on vessels where incidental lubricant discharge could occur in the marine environment. Those applications include stern tubes, thrusters, stabilizers, CPP propellers, and wire rope and mechanical equipment immersed in water during normal operation.
Today, with so many EAL choices available, vessel owner/ operators and equipment manufacturers are looking to understand the performance characteristics of these different lubricants. Other than water lubricated applications, EALs attain their environmental qualities by using either an ester oil, a polyalkylene glycol (PAG) oil, or a combination of ester and synthetic hydrocarbon oils (PAO) as the base oil of the lubricant. Considering that the vast majority of EALs that have been approved by seal system manufacturers contain ester oils, it is likely that most vessels will use an ester-based EAL. It is important for users to have an accurate understanding of ester oil performance characteristics to assist in their selection of EALs and to ensure they receive the most benefit from their investment.