James Walker studies effects of environmental lubricants

London – With the growing enforcement of legislation promoting the use of environmentally safe lubricants, there is an urgent demand throughout the industry to fully understand the effects on seals and other components of a switch to such lubricants.

Fluid sealing producer and global manufacturer James Walker has been involved in carrying out test programmes on ‘Environmentally Acceptable Lubricants’ (EALs) to optimise seal designs and materials to provide high performance and longevity when operational in a propulsion system.

“Initially viewed as a simple chemical compatibility issue, the James Walker test programme has revealed that seal materials used in dynamic propulsion systems do in fact need to be validated as actual finished seal products rather than simple material samples,” said a recent report by the company.

This is due to a number of factors that can influence seal performance including temperatures in the shaft contact area and the condition of the lubricant, particularly in relation to levels of water contamination.

James Walker announced that due to “increasing pressure from designers and manufacturers of marine propulsion systems”, the company has now gone public with the results of the tests completed to-date.

“Switching to EALs may well be of proven benefit to the environment,” said the company adding there is likely a potential minefield of hidden costs for the ship owners and operators in terms of additional maintenance and reduced equipment performance.

It has been identified that the condition of the oil can influence rubber compatibility, in particular water content due to contamination.

“This not only reinforces the importance of testing seals on water/oil interfaces, but has directly affected our immersion testing regime,” said the report adding that “as a result we not only conduct immersion tests on pure oils, but also as oil and water mix.”

The results achieved to date have now been published by James Walker in a short research paper, which includes a material compatibility matrix  highlighting material performance in a range of the most commonly used EALs.

The following tables highlight some of of James Walker’s findings.