3 ATEX Horizontal Centrifugal Pumps for Diesel Export and Transfer

In this case study, we are discussing a project we supported for an engineering contractor operating in the Pacific region. This particular client was managing the construction of a bulk petroleum storage tank at an oil terminal. 

They were looking for three new ATEX-rated pumps that would be used for the transfer and export of diesel within the new oil facility. 

What is the best pump for this type of application?

It is important when handling fuels, chemicals or other volatile liquids that the right pump design is chosen to meet the requirements of the type of fluid and performance levels required. When contractors are looking to transfer and export a fluid like diesel there is a wide selection of pump technologies available.

Selecting the right pump is critical

If the fluid needs to be transferred at medium to high pressure, a positive displacement pump would be a good option. These pumps ensure that siphoning of fluid doesn’t take place and also provide a guarantee of duty point.  

A pump’s operating point or duty point is where the pump and pipework capabilities meet. This means that the pump will always operate at the point where the system and pump curves intersect. At this point, there is a perfect balance between what the system needs and what the pump can deliver. 

Another pump option is a long-coupled type of design. This gives a number of advantages including easy access so that the pump can be serviced in situ without disconnecting it from the pipework.  

In this specific application for our client, the required flow was high, but the pressure required would be low at just 10m head. For this customer, a long-coupled centrifugal transfer pump would be a smart choice. It would deliver the high flow at the pressure required very cost-effectively, as the viscosity of diesel is very close to water. 

The key design features of a long-coupled centrifugal transfer pump

Overall, a long-coupled pump design is very easy to maintain as the pump head can be accessed and worked on without having to remove the motor.  

In addition, the centrifugal pump format has additional bearings installed in the pump head to share the operational workload. This makes it more robust and able to operate continuously as the extra bearings take a great deal of strain away from the motor during operation. 

To summarise the key features of the design chosen were: 

•  Separate motor 

As a separate standalone component, this can be replaced easily. In addition, the motor is available worldwide and almost certainly locally if there is an emergency  

• Easy component replacement 

If just the pump shaft needs replacing, this can be done simply without disconnection of the pump from the system, with the motor remaining in situ. 

• Reduced motor strain 

Separate bearings located on the pump head take on a large part of the workload, reducing stress and strain on the motor 

• Longer lifespan 

As well as the additional bearings in the pump head, separate shafts also help to spread the workload more evenly, extending the pump's lifespan 

• Better protection against fluid leaks 

In a long-coupled design, the space between the pump and motor drastically reduces the chance of fluid getting in the motor if the seal fails 

• Easy maintenance 

The simple design gives quick access to the pump head for repairs or replacements without having to disconnect the motor first 

Where are long-coupled centrifugal transfer pumps used?

Long-coupled centrifugal transfer pumpsare ideal for use in a range of heavy duty applications in the industrial and marine markets.  

Typical applications include fuel export and transfer, agricultural irrigation, water treatment and supply, wastewater pumping with low solid content, energy plants, mining, firefighting, dewatering, building systems including high-rise building water supply, marine and cooling/heating conditioning (HVAC). 

What was our specification for this client?

At North Ridge Pumps, we are not tied down to specifying just one type of pump. 

As Britain’s biggest pump supplier with over 25 years of experience, we can select any kind of pump for any kind of client and application.  

In fact, we draw on our expert knowledge to come up with the optimum specification for every client – not just a pump straight off the shelf. Most important of all, we always select the pump design which is the most cost-effective option.  

A tailor-made pump design

For this client in the Pacific, we selected three of our XHLE horizontal diesel transfer pumps. These are large heavy-duty units offering high flow and high-pressure capabilities.

They are specifically designed to pump low viscosity clean or slightly contaminated fluids including fuels like diesel, petrol and kerosene, as well as sea water and fresh water. They also offer ATEX-rated versions which are modified for handling flammable fluids or operating in a hazardous environment.

The pumps were long-coupled and mounted on a baseplate fitted with a 7.5Kw IP56 1,200rpm ABB ATEX motor operating at 60Hz. Normally pumps can operate as high as 3,600rpm. However, these pumps will usually be working at one third speed, so they are configured to give many years of service and need little to no maintenance.  

In addition, the diesel transfer pumps were manufactured with a casing made from strong and durable ductile iron, with impellers and shafts formed from stainless steel AISI 316. The pump was painted in anti-static paint, with an anti-sparking brass coupling guard for additional safety.

Fully tested performance

The XHLE units were designed to deliver 2500L/min at 10m head. In accordance with ISO 9906:2012 Gr2B certification, we supplied the pumps after carrying out rigorous pump performance tests. 

During the test, the pumps were rated for a maximum of five duty points which include the rated point, shut-off and three more points.  

As the table below shows, an acceptance grade of 2B shows the variation in flow and pressure that would be required to confirm that the diesel transfer pumps would be acceptable. For grade 2B as shown this equates to + - 8% for flow and +- 5% for pressure. 

If you have a transfer application handling any kind of fluid and are unsure which pump is right for you, contact North Ridge Pumps now to see how we can help you.

For more information on 3 ATEX Horizontal Centrifugal Pumps for Diesel Export and Transfer talk to North Ridge Pumps Ltd