Industry Insight: Bio-Oils and the Dangers of Electro-Static Charging

Damage to a tank caused by the formation of varnish on the surfaces.

Environmental legislation in shipping has had a significant impact on the way ships are operated, and in recent years environmental regulations have become increasingly stringent with an added emphasis on monitoring compliance.

A recent example of this is the introduction of the Vessel General Permit (VGP) in December 2013, which mandates that most commercial ships operating within three miles of the coast of North America must use Environmentally Acceptable Lubricants (EALs), which come at a higher cost than traditional lubricants.

Such is the impact of this regulation that the International Maritime Organisation's (IMO) Maritime Safety Committee (MSC) is now recommending similar guidelines for ships operating in polar waters, affecting an increasing percentage of the shipping industry.

Bio-oils compliant with the VGP have a low zinc content, affecting the properties of the oil including decreasing its conductivity. All hydraulic fluids are sensitive to electro-static charging when being pumped trough a system or flowing through filter media, and any source of friction in the system can create electro-static energy.

Oils with good conductivity are able to distribute this charge more evenly through the fluid, preventing a build-up of charged particles in small areas. With a lower zinc content, the fluid is less able to distribute electro-static energy meaning that charged particles can accumulate, leading to a sudden discharge.

The sparks created by this discharge cause damage to both elements within the system and the oil itself, including burning holes in the filter media. Further damage then occurs when the thermal and oxidative degradation of the oil leads to the formation of varnish on the surfaces of the system, creating blockages, generating a slower response for system components and causing valves to stick. This has a significant effect on the operational efficiency of the system and potentially creates the need for additional maintenance and unplanned downtime.

The damaging effects of electro-static charge can be minimised by managing the build-up of charged particles and limiting the sources of excessive friction within the system, thereby optimising efficiency and preventing the need for repairs.

Parker HFDE has researched this extensively and has developed a range of solutions to best identify and manage these issues. One important measure for example would be to limit the static energy generated by filters, one of the greatest sources of friction within the system.

Parker Static Control Media filters lower the overall impact of electro-static charge and therefore minimise the risk of sudden discharges. These filters can be combined with support offered by Parker in effective analysis of the condition of the oil which will help to identify any issues before too much damage occurs.

Parker also support with identifying the operational state or potential contamination of the system components, as well as the condition of filter elements. With a detailed analysis of the hydraulic system, ship owners can ensure they are complaint with the VGP whilst mitigating against the risk of damage and unplanned maintenance.

When moving from non-compliant lubricants to more costly bio-oils, ship owners must have an in-depth knowledge of how EALs react when subjected to the same operational processes and understand how to identify and manage the effects of this.

Without this knowledge, ship owners may find themselves facing unexpected repair bills and costly downtime. When combined with the elevated cost of EALs, this then makes compliance unaffordable.

However, non-compliance carries the risk of hefty fines, thereby creating a lose-lose situation. By limiting static build-up in the oil and effectively analysing the condition of the elements within the system, ship owners can manage the impact of converting to bio-oils, and therefore ensure that they can mitigate against the financial risks.