Vertical Inline Centrifugal Pump for Diesel Transfer in the Maritime Industry 

This case study explores a project for one of our maritime clients where we provided two ATEX VXEN vertical inline centrifugal pumps equipped with Siemens IE3 ATEX motors for transferring D2 Diesel (Gasoil).

Specific project requirements 

The client required two cargo oil pumps to transfer D2 diesel from cargo tanks on a ship to the shore. They needed to discharge the entire fuel load within a maximum time frame of 10 hours, with a pump capable of operating continuously for up to 14 hours. The customer had existing 200mm pipework which they were unable to upgrade, and they wanted the connection of the pump to the pipework to be as seamless as possible to prevent contamination and maximise reliability. Durability and ease of maintenance were also a design priority as the client was based in Guyana, where sourcing parts and materials for repairs can be problematic.

Key challenges with transferring diesel from a vessel cargo bay 

 Selecting a pump for the transfer of diesel from an on-vessel cargo bay involves several considerations: 

Design: Space is at a premium aboard any ship. The layout of the vessel in this particular case meant that horizontal space was extremely limited: a vertical pump design with a smaller footprint was required.  

Operation: Modern ports are busy and vessels have limited time in the docking bay to discharge their cargo. Any delays can lead to costly demurrage charges for the ship owners, so pumps must be able to operate efficiently and continuously for several hours.

Safety: A light fuel pump was required as this project involved the transfer of D2 Diesel. GasOil is classified as a flammable liquid (H226), so both pump and motor in this case required ATEX certification. Contaminated D2 Diesel can cause serious safety concerns for the end user such as reduced engine performance and total engine failure, so the transfer system also had to minimise the risk of fuel contamination. 

Vertical Inline Centrifugal pumps – our solution 

We supplied two ATEX-certified VXEN vertical inline centrifugal pumps, equipped with Siemens IE3 ATEX Motors. This system delivered on the client’s requirements in several ways:

• Low initial investment costs

Our vertical inline pumps had simplified piping arrangements and a smaller footprint, which served to simplify the installation process and reduce installation costs. 

• Ease of maintenance

The VXEN vertical inline centrifugal pump has a back pull out design that allows the motor to be removed while the pump is still connected to the pipework. This reduces the downtime required for the pump to be serviced/maintained.

• Operating times and efficiency

We were able to specify the pumps for a flow rate of just over 3000L/min, enabling the tank to be emptied in just over 6 hours – four hours ahead of their target time - reducing the likelihood of demurrage. The Siemens IE3 ATEX motors were rated for continuous operation, exceeding the brief requirements for operation of up to 14 hours a day 

• Profit margins

Loss of fuel through inaccurate transfer measurements can affect the client’s bottom line. We supplied two oval gear metres with a 24v local display which were accurate to within 0.5%, thus allowing for accurate measurement of dispensing and amounts transferred. This ensured that the client could account and bill for all fuel transferred.

• Adaptation to existing infrastructure 

The pumps were supplied with counter flanges that transitioned from DN150 on the pumps to DN200mm. This matched the onsite pipework and ensured a seamless integration without the need for replacing any of the existing infrastructure. The counter flanges conformed to EN 1092-2 / PN 16 for steel and stainless-steel casings. 

• Compact design

The vertical centrifugal configuration of the pumps offered a compact footprint, with the motor affixed atop the pump, and straight-line alignment with the pipes at both inlet and outlet. This was crucial as horizontal space aboard the vessel was limited.

• Durability

Our pumps were designed with durability in mind. The pump casing was made from ductile iron, enhancing the pump's ability to withstand high pressures (up to 100m) without damage. In addition, the pumps had low NPSH requirements, reducing the risk of dips in performance, and of damage from cavitation and wear and tear. Both the centrifugal pump and motor had independent shafts for added robustness. This means that only the pump shaft would need to be replaced in the event of a breakdown.

These diesel transfer pumps were also fitted with bronze wear rings which help to maintain operational clearances and efficient operation, while simultaneously protecting the impeller and the main pump casing from wear. Additionally, a lantern bracket was installed between the pump and the motor, creating a space to protect the motor from fluid ingress in the case of a seal failure. These features all served to prolong the overall life of the pump and reduce the costs associated with repairs and downtime.

• Safety

Both the VNEX vertical inline pump and the Siemens IE3 motor were ATEX certified, being safe for use in explosive environments and the handling of flammable liquids. Anti-static paint was used on the pump and motor to prevent sparks and the build-up of static electricity inside the pump itself - a critical safety measure when handling flammable substances like GasOil. The pumps were also designed to deliver safe high-volume transfers, avoiding the risk of the tank becoming over-pressurised if overfilled.

VXEN Vertical Inline Centrifugal pump – key features

North Ridge Pumps are an independent manufacturer of pumps. We aren’t tied to a single pump technology, so we can select the most appropriate pump for your application. Our solutions aren’t limited to pumps – we can also provide flowmeters and complete pump kits where required. 

If you have a pump you need specifying for a fuel transfer application, contact us on 01773 302 660 or sales@northridgepumps.com to see how we can help.