Fuel quality & resilience testing

Testing frequency depends on the criticality of the application and the storage conditions. For standby generators supporting critical infrastructure, we typically recommend a minimum of annual testing for low-risk sites, quarterly for moderate-risk (such as locations with known water ingress history or high biodiesel blends), and continuous monitoring for highest-criticality applications. HVO fuel generally has a longer oxidation stability, but still requires periodic assessment — particularly for water management and material compatibility.

HVO (EN15940) behaves differently to EN590 mineral diesel in several important ways. It is not hygroscopic in the same way as FAME-blended diesel, but water can still accumulate in the storage system. It is also incompatible with some elastomeric seals, hoses and coatings found in older fuel systems. Testing protocols need to reflect the specific characteristics of the fuel type in storage — what applies to EN590 does not always apply directly to EN15940.

Yes, they are simple to use. Our team can give you a run-through of how they work, but essentially you just need to connect them to power, connect the hoses, pop the lances in the fuel tank and switch it on! The filter changing process is extremely simple, too.

Fuel polishing is the process of circulating stored fuel through high-efficiency filtration to remove contamination and restore it to a usable specification. It is typically recommended when testing reveals particle counts above target ISO 4406 levels, visible free water or elevated Karl Fischer water readings, microbial activity (ATP or culture results above threshold), or visually apparent sediment or discolouration. It is also used proactively as part of scheduled maintenance programmes for high-criticality sites.

Contamination does not distribute evenly throughout a storage tank. Free water is denser than fuel and sinks to the bottom. Microbial biomass (the diesel bug) forms at the fuel/water interface — at the very bottom of the tank. Particulate contamination also tends to settle over time. If you only sample from the top of the tank, you will almost always miss the contamination that poses the greatest risk to your fuel system. We sample from the top, middle and bottom of every tank in accordance with ASTM D4057 and ISO 3170.

A fuel resilience programme is a structured, ongoing approach to managing fuel quality and storage system condition. Rather than testing only when a problem is suspected, a resilience programme establishes a scheduled cadence of testing, monitoring, maintenance and documentation. It typically combines periodic laboratory and on-site testing, continuous or periodic condition monitoring, scheduled fuel polishing and water removal, regular tank inspection, and a clear corrective action framework. For sites where fuel failure is not an option, a resilience programme provides documented assurance.

Yes. For sites that require very frequent testing — weekly or fortnightly — or where regular third-party access is impractical (such as government or high-security facilities), we can provide testing kits, equipment and training to enable your own maintenance team to conduct routine sampling. Samples can then be returned to us for certified laboratory analysis when required.