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Posted on: 22/10/2020

Tank Maintenance Reminder - the importance of a proactive approach

Tank Maintenance Reminder - the importance of a proactive approach

CPS Fuels Commercial Customer Advice Sheet

Reminder: Taking a proactive approach to Tank Maintenance and Water Management in Autumn and Winter for tanks that store RTFO Fuels containing FAME

As we move towards the cooler and wetter months of autumn and winter we once again wish to highlight the importance of taking a proactive approach to tank maintenance and water management.

Renewable Transport Fuel Obligation:

The government's Renewable Transport Fuel Obligation (RTFO) requires a percentage of petrol and diesel in the UK to come from renewable sources. This means the addition of ethanol in petrol and the addition of fatty acid methyl ester (FAME) in diesel.

The presence of such renewable sources in petrol and diesel make water and tank management, throughout the supply chain, more important than ever. In recognition of this challenge, we continue to invest, communicate and work with our supply chain to ensure only the highest quality of fuel is supplied to our customers.

Diesel Fuel: Supplied by CPS Fuels, unmarked as Diesel, or marked as Gas Oil (Red Diesel).

In order to comply with the RTFO, diesel fuel in the UK now contains up to 7% of renewable bio diesel (FAME). FAME has certain characteristics which can result in complications if diesel storage tanks are not looked after correctly.

Complications relating to FAME:

  1. FAME has solvent type properties which have a 'cleaning effect' on fuel tanks. This cleaning effect can remove dirt and result in clogged filters.
  2. FAME also has 'hygroscopic characteristics' meaning it attracts and holds on to water. Water in diesel fuel can lead to the growth of microbes (Microbiological contamination).


What is microbiological contamination?

Microbiological contamination results from the growth of microorganisms, such as bacteria, fungi, and yeasts. Such microorganisms will grow wherever there is a source of water and fuel (as food).

Filters in pumps play an important role in protecting consumer's engines from particles (dirt) in fuel. However, microbiological growth can result in the blockage of pump filters, impact the performance of the pumps (blocked filters will lead to slow delivery and nozzles out of action) and lead to increased corrosion.

Important: As FAME helps to attract water into diesel fuel, it is now more important than ever to ensure that water is kept out of the storage system to reduce the risks outlined above. This is especially important in the cooler and wetter months of autumn and winter.


How can water get into the fuel storage system? Entry points for water include:

  1. Free water can occur due to ingress or leaks as a result of, for example, heavy rainfall or through cracks in equipment
  2. Water vapour (humid air) can enter storage tanks through air vents followed by cooling or condensation on tank walls

What can I do to help avoid issues associated with water in the fuel tank/storage system?

  • Routinely inspect the fuel storage system for areas of possible water intrusion:
  • Verify that tank lids and fill caps are securely in place;
  • Ensure gaskets are not cracked or worn;
  • Check that spill buckets are clean and dry;
  • Verify that the steel vent line riser is not corroded at the base where water could intrude; and
  • Ensure that any surface drains near the underground tanks are clean and free of debris.
  • Conduct checks to ensure that tanks remain free of water. Use water-finding paste to detect the presence of water at the bottom of the tank.
  • Monitor dispenser flow rates for slow flow and if indicated, change the filters.
  • Pump filters should be checked regularly to avoid the build-up of sludge content.
  • Consider the use of a fuel storage or conditioning additives.

CPS Fuels have a very experienced tank engineering team who would be pleased to provide help, advice and assistance to all our commercial and agricultural customers so they can bring their installations up to scratch and so ensure that the fuel they store is kept and dispensed in the best possible condition.

If you have any queries, questions, or require any further advice the please contact the CPS Fuels Commercial Team on 01953 713540.

CPS Fuels

CPS Fuels, as a JET Approved Partner, supply marked EN590 grade diesel as Gas Oil so you have the highest quality Gas Oil available irrespective of use. CPS Fuels Gas Oil meets the same BS EN590 specifications as white road diesel and is therefore suitable for use in all farm machinery. The fuel properties of EN590 (as Diesel & as Gas Oil) are adjusted seasonally to maintain good low temperature performance and operability.