North Ridge Pumps supplied four heavy-duty horizontal multistage pumps to a client requiring the transfer of diesel at 30 bar pressure and a flow rate of around 60 m³/h. Since the client prefers to mount their own motor and baseplate, the pumps were provided in bareshaft form. They are being used at a thermal power plant to convert heavy fuel oil (HFO) into diesel.

What’s the difference between HFO and diesel?

HFO is a heavy, high-sulphur fuel from crude oil distillation, mainly used in shipping but requiring heated storage. Diesel is lighter, low in sulphur, widely used in transport and machinery, and easier to handle with no special storage needs.

Why might a power plant change from HFO to diesel?

The switch may be made for several reasons, such as:

  • Environmental compliance: Switching from HFO to ultra-low sulphur diesel cuts sulphur dioxide emissions by 99% and reduces particulates and CO₂ by ~70%.
  • Fuel price and supply: HFO is cheaper, but diesel may be preferable if HFO prices rise or supply becomes unreliable.
  • Operational flexibility: HFO requires heating and performs poorly at low loads, while diesel flows easily and ensures stable combustion.
  • Efficiency and maintenance: Diesel avoids engine problems linked to HFO at low loads, improving performance and reliability.
  • Availability: Diesel is often more practical for remote areas lacking consistent HFO supply.

However, diesel offers cleaner, more reliable, and cost-efficient operation.

Multistage Pumps – Advantages and Applications

Multistage pumps use multiple impellers in series to generate high pressure efficiently, saving energy compared to single-stage pumps. Their vertical design also reduces floor space needs.

They are ideal for applications requiring high discharge pressure or vertical lift, such as:

  • High-pressure fluid transfer in chemical, oil, and gas industries
  • Water supply for high-rise buildings and long-distance pumping
  • Industrial cleaning and power washing
  • Supplying water to high-pressure boilers
  • Reverse osmosis in desalination plants

Why specify horizontal multistage pumps for this application?

We specified horizontal multistage pumps because they reliably deliver 30 bar pressure at 60 m³/h, meeting the client’s brief for four heavy-duty diesel transfer pumps, while also offering flexibility through variable speed drives and multiple outlet options.

A multistage pump with eight ring stages

To produce the level of performance demanded by our client, we came up with a clever solution for these heavy-duty diesel transfer pumps. Each one incorporated eight ring stages, each one consisting of an impeller, suction and discharge diffuser to deliver the required pressure and flow rate.

In addition, our range comes with the option of rotating the suction and discharge flange to match the existing pipework, removing the need for any changes to pipework.

For high-pressure, high-flow fluid transfer applications, contact North Ridge Pumps for expert advice.