What Do I Need to Know About Long Term Diesel Storage?

Here’s good advice if you are relying on diesel as a back up fuel in the Pacific NW.

Now is the time to refill and treat your back up fuel tanks.

Quite a bit of our business at Star Oilco is fueling back-up generators, emergency water pumps, refrigerated trailers and other long term off-road diesel storage requirements. In the Pacific Northwest, biodiesel blending is required by state laws and you need to take an extra duty of care when storing diesel as a back-up fuel.

This means that most off-road diesels and heating oils are ultra low sulfur diesel containing a small quantity of biodiesel.  That means long term storage requires a proactive approach.  You can’t just hope and wait to see what the fuel begins to look after years of storage.

Technical advice from Government Fleet Magazine to help you with storing diesel fuel.

Here is an article from Government Fleet Magazine on the subject which runs through the specifics of long term storage and what causes fuel to degrade when stored.  Government Fleet Magazine – How to Maintain Stored Diesel Fuel.

Star Oilco has also worked up a PDF check list on how to verify if your fuel is in need of freshening or is still in emergency ready shape.  If you are a customer of ours, we will deliver a laminated card version to keep next to your back up generator. If you are not a customer (or outside of our service area) drop us a message below and we will gladly email you the PDF.

For our customers, we recommend that you check the tank bottom fuel quality on an annual basis to make sure the product looks good. If the tank has sat for years and is dark in color (good diesel is bright and transparent – you will notice if it is in bad shape), we recommend pumping the tank out at least partially and replacing with fresh fuel. Often you can also hugely improve the quality of the fuel by polishing the fuel. Polishing is when you circulate fuel from the bottom of the tank through a pump, filter repeatedly in order to remove any sediment or growth from the fuel, and then place this fuel back in the same tank.

Look at your fuel for a bright and clear color.

For stored fuel, you also want to make sure it is stabilized and contains a biocide. Stabilizers prevent the oxidation of the fuel and prevent the effect of metals like lead, copper and zinc, which can react and degrade fuel. For heating oil systems with a return line, for instance, the fuel is flowing through a copper line to the furnace and then back to the tank in a return line.

Use additives designed to prolong the life of your emergency diesel fuel.

Biocides prevent the growth of biological activity in the tank. In scenarios where micro-organisms like algae, bacteria, yeasts, and other bugs are growing in your fuel, biocides can kill this growth. It is still important to remove the residual grit and other contaminants that are the hallmark of bugs growing in your tank. Usually you remove them by filtration or total turn over of the fuel. If your tank absolutely has to be clean, you can contract a tank professional to enter the tank and physically clean the tank bottom or reline the tank with either fiberglass or an epoxy resin.

Water in diesel destroys fuel quality rapidly. Check your tank for water every fall and spring.

In events where water finds its way into your storage tank, that can also be corrected by pumping the tank bottom. Additionally, you want to put in an absorbent material designed to absorb water and not fuel. If your long term storage tank has water and you are not planning to burn 100% of the fuel in the near future, DO NOT add anything that removes water by distributing into the fuel. Adding a “fuel drier” that actually pushes the water into solution with the diesel will worsen the long term quality of your fuel, not improve it. That water is where bugs find their home to grow in fuel.

Star Oilco will test your fuel at no charge if you have an open account.

Feel free to call us with any questions you may have about long term storage of diesel. Star Oil can also deliver treated diesel ready for long term storage complete with Hydrotex PowerKleen Premium Diesel additive to improve the long term storage quality of your fuel. For biocide, we use Valvtect BioGuard fuel microbiocide to kill any possible biological activity and prevent any chance of it starting.

If you have a long term diesel storage tank and you are in the Portland, Oregon area, we are here to test your fuel.  Make sure your diesel is there for you when disaster strikes.

For more reading on diesel fuel quality assurance:

Fight Humbug in your Diesel Tank (using Valvtect Bioguard Plus 6 to stabalize your stored diesel)

Diesel Fuel Technical Review (an easy to read and free text book on diesel fuel)

Emergency Back Up Generator Fuel Quality (designed to provide a checklist to help Facility Managers keep those back up generators ready for emergency action)

Using Desicant Breathers to keep diesel fuel dry and clean (an introductory primer on desicant breathers and how they can be used to keep long term diesel storage drier and cleaner)

Using Diesel Filters to clean up your diesel fuel quality (an introductory primer on using aggressive filtration in line with diesel fuel dispensing for fuel quality assurance)