Fuel tank cleaning, & fuel management services

From on-site tank cleaning to complete fuel infrastructure management – protecting your operations from the inside out

Essential guide to fuel polishing

A free pocket guide with everything you can do to maintain your fuel.

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On-site fuel cleaning

Certified fuel cleaning to EN590 and ISO 4406 18/16/13 standards

If you do not have a fixed fuel polisher fitted, we can provide on-site regular or one off fuel cleans. Our high-flow cleaning rigs generate turbulence within the fuel storage tank, disrupting contamination pockets that build up in low-turnover tanks and forcing contaminants into the cleaning system. The result is fuel that is certified clean to EN590 and ISO 4406 18/16/13 standards.

What fuel cleaning removes

  • Water – Reduced to 200 parts per million or less, as specified in EN590
  • Solid particulates – Soot, rust, colloid carbon and settled sludge
  • Microbial growth – Diesel bug and the biofilms on tank surfaces that polishing alone cannot reach

How we work on-site

  • Discreet attendance – Our team arrives in an unmarked van — no concern raised with customers or staff
  • Minimal disruption – Generators do not typically need to go offline during the clean
  • Any site type – Outdoor depots, indoor tanks, basements, rooftops and confined spaces — all covered
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Links & Downloads

Bank, data centre case study

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Is your fuel putting your operations at risk?

Our on-site service is comprehensive by design, each visit is carried out by the original manufacturer’s engineers — giving you access to OEM parts, full fault testing, and ongoing peace of mind.

Who we work with

Our services are relevant to any organisation that stores fuel. We are a trusted partner for:

Critical power

Hospitals, data centres, telecoms, STOR and FFR – where backup power must be dependable.

High-security sites

MOD, government facilities and corporate headquarters, with security clearance as standard.

Marine

Ship bunkers and dockside storage, including limited-access and confined-space locations.

Industrial & commercial

Manufacturing, logistics, retail parks, and facilities management for single or multi-site operations.

Rail & aviation

Where fuel reliability and regulatory compliance are non-negotiable.

Dispersed locations

From rooftops to remote sites, we can access your stored fuel anywhere.

certified standards

Ready to protect your fuel supply?

Our field teams can be on your site fast — with all the equipment needed to test, clean and protect your fuel to certified standards, with minimal disruption to your operations.

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Brands we’ve worked with:

Fuel management services for critical infrastructure & data centre power

Ready when you are

COMPLETE FUEL PROTECTION

Complete fuel infrastructure management

We are a full-service fuel management partner. Beyond tank cleaning, we provide the full range of services needed to manage, maintain and future-proof your fuel storage infrastructure:

Fuel testing

Real-time on-site analysis of fuel cleanliness. Results delivered immediately, backed by a full laboratory report.

Fuel polishing – Diesel Defence

Fixed or mobile polishing systems that circulate and filter fuel daily, preventing contamination regrowth.

Fuel additives

All-in-one fuel treatment that stabilises stored fuel for up to 2 years, lubes pumps and kills bacterial growth.

Tank testing

Scheduled OFTEC inspection of tanks. Comprehensive condition report with recommendations.

Tank decommissioning & install

Full removal and disposal of redundant tanks. commissioning of new replacement tanks.

Fuel uplift

When fuel is beyond recovery, we provide compliant removal – from standard rebated uplift to EA-registered waste disposal.

Switching to HVO?

Switching to HVO – further considerations

HVO is generally safe and beneficial for older diesel generators, but switching from diesel can expose pre-existing tank contamination, cause minor seal shrinkage in very old engines, and reduce peak power by 1–3% due to fuel density differences. The main risks are operational rather than mechanical, and they are easily managed with good fuel housekeeping, filter discipline, and ensuring the HVO meets EN 15940.

Fuel cleanliness — HVO exposes existing contamination

HVO itself is exceptionally clean, but it does not dissolve deposits the way diesel can. Switching from diesel, HVO can cause:

  • Loosened tank sludge entering fuel lines
  • Filter clogging
  • Injector fouling (if contamination is severe)

Symptoms

  • Filters blocking shortly after conversion
  • Engine hunts or derates under load
  • Hard starting after storage

WASP recommend that any switch to HVO from the traditional fossil fuels includes a complete fuel tank clean prior to the changeover due to evidence of HVO stripping debris, sludge and sediment from the inside of the tank if used as a drop in alongside diesel or as a full replacement. Failure to clean the tank prior to using HVO could lead to diminished outcomes for the emissions, smoke and fumes reduction along with the potential for the disturbed sludge etc. damaging the injectors and blocking filters.

Advice

The hidden threat: What’s really in your fuel tank?

Fuel contamination builds silently over time. It can arrive with a dirty tanker delivery, or develop in storage as water enters through rust, damaged seals or displaced breather caps. Biodiesel is particularly vulnerable — it is hygroscopic, meaning it actively attracts moisture from the atmosphere. Once water is present, bacteria multiply rapidly, forming diesel bug: a thick, jelly-like growth that clogs filters, injectors and standby generators.

Tanks with low fuel turnover — such as emergency generator tanks — are especially at risk because the fuel sits undisturbed for long periods, accelerating degradation.

Water ingress

Enters via atmosphere, rust and new deliveries. Biodiesel actively attracts it. Accelerates all other contamination.

Diesel bug

Microbial growth that thrives in water layers. Creates sludge that clogs engines and generators.

Solid particulates

Soot, rust and carbon deposits settle as sludge and cause long-term damage to fuel system components.

When fuel polishing isn’t enough

Fuel polishing — circulating fuel through filters — is highly effective for ongoing maintenance. But when contamination is severe, polishing the fuel alone won’t resolve the problem.

Think of it like drinking orange juice from a glass: the juice may be gone, but the glass is still coated in residue. Polishing fuel inside a dirty tank leaves sludge, biofilm and microbial colonies on the tank walls and floor. Freshly cleaned fuel will be recontaminated almost immediately. In these situations, the tank itself must be cleaned first.

When man-entry cleaning is required

For the most severely contaminated tanks, man-entry cleaning may be necessary. Our operatives hold confined space qualifications and are fully equipped with breathing apparatus, body harnesses, PPE and gas monitoring equipment. A minimum of two team members are always present. The tank is re-certified before fuel is returned.

Fuel is uplifted and polished separately from the tank, and trained operatives will enter the tank to clean it.

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