Avoid generator fuel tank contamination and unnecessary downtime

For businesses reliant on an uninterrupted supply of electricity – most manufacturing production factories operate around the clock – dealing with a power outage is a crucial part of good business continuity.

But how reliable is the standard back-up plan for most businesses, the diesel generator?

The British Standards Institution has passed legislation (BS5410-3: 2016) demanding the introduction of bio content into existing fuels. Generators that use biofuel require preventative maintenance if they are to perform reliably on demand. 

The potential pitfalls

New biofuels contain added FAME (Fatty Acid Methyl Ester) when compared to petroleum derived diesel. This puts an end to the ‘fit and forget’ days of generators.

The FAME content in biofuel is hygroscopic. This can have far-reaching implications for the health of fuel held in tanks. Any water that makes its way into biofuel will be absorbed and held in suspension. 

The FAME content in biofuel is hygroscopic. This can have far-reaching implications for the health of fuel held in tanks

This layer of suspended water provides ideal conditions for bacterial growth. The water clings to tank walls and microbes – known as fuel bugs or diesel bugs – grow at the fuel-water interface.

These microbes feed off dissolved oxygen and nutrients in the fuel, enabling their growth which in turn adds more water content to the fuel as hydrocarbons are broken down in the process.

In no time at all – given that the bacteria can double in size every 20 minutes - these microbes will coagulate to form sticky, slimy polymers in strings and films (sludge). Herein lies the problem. Sludge in fuel tanks will block fuel filters, fuel lines, and injectors; all of which can add up to cause complete system failure.

Further problems are caused by the by-product of the bacterial action discussed, acetic acid. It will corrode steel, brass and copper, meaning that vital engine components such as fuel pumps and injectors can succumb to its destructive force.

Poorly maintained generators can fail when put to the test. This presents an expensive issue to fix. The full process of emptying contaminated fuel, cleaning, repairing, and refuelling can take three days, during which a considerable cost to business will be incurred. 

Step by step solutions

So, if you are not incorporating measures of preventative maintenance within a continuity plan, start now. 

To begin with, conduct an independent analysis of your fuel to assess the risk of fuel contamination issues.

Next, instigate a professional test and trend service regime to monitor your fuel hygiene over time and to identify changes in its condition. As an example, the OTS service costs approximately £1,000 per annum per tank for four visits.

You should also turn your entire volume of fuel every thirty days and only purchase your fuel from FPS-certified distributors.

Be aware too that fuel-oil companies recommend a time limit of three months when you are storing biodiesel.

Lastly, do ensure your generator apparatus (fuel polishing system, fuel filters including inline ‘basket’ filters etc.) is tested and certified to meet SAE: J14882010_10. This test procedure will determine the ability of the fuel/water separator to function effectively.   

Steve Gain is managing director of Oil Tank Supplies (OTS)