New Road, Cragg Vale, Hebden Bridge, West Yorkshire, HX7 5TT
0808 164 4570

York Teaching Hospital NHS Foundation Trust

York Teaching Hospital NHS Foundation Trust provides a comprehensive range of acute hospital and healthcare services across North Yorkshire and East Yorkshire.

The Problem

The hospital operates 24/7 and has a number of systems in place to ensure their service is uninterrupted. One such service is an emergency backup system which provides power in the event of an issue with the main electrical supply. York Teaching Hospital operates a Gas Oil powered backup generator system fuelled from a 90,000 litre storage tank. The NHS Trust proactively made contact with Craggs Environmental to establish if their stored fuel remained within specification as it had been stored for a significant period of time.

A Craggs Environmental Fuel Sampling Team visited the site and took a core sample (top, middle and bottom) from the storage tank. This sample was used to test the fuel to check the quality and highlight any associated risks. Upon completion of the Craggs Environmental in-house laboratory test for both water content and particulate level the trust was advised that the fuel was out of specification (BS 2869 A2) and required maintenance to reduce the risk of potential stand-by generator problems. The trust requested that Craggs Environmental complete a fuel remediation process to bring the Red Diesel back to specification.

The Solution

To complete this work Craggs Environmental deployed a fuel filtration vehicle and a fuel tanker. Upon arrival the engineering team began by removing the bulk of the sludge/water from the base of the tank using a reverse action pump on the fuel tanker. When this had been completed the fuel polishing process could begin using a multi-pot filtration rig. This fuel filtration rig operates similar to a kidney dialysis machine in that the “fuel” is passed through multiple filters to remove both water and particulate (sludge). The filtration system reduces the particulate count down to 1 micron which is in line with refinery grade specification; this is confirmed by the equipment’s built-in telemetry system.

The Outcome

Over a process of 5 hours, 50,000 litres of fuel was filtered back to within specification. This process has extended the life of both the fuel and the tank itself by removing the harmful sludge/water.

As part of a maintenance programme York Teaching Hospital identified the possible risks of storing bulk fuel for a critical application. If you store fuel for a critical application or have any concerns then please contact our team on 0808 1644570 or email

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