Comparing 4" Borehole Pumps

If you are looking to buy a borehole pump and search the internet, you will find quite a few different brands. Naturally, every seller or manufacturer claims they offer the best pump. And 'yes', we do the same (we are only human), but we like to back it up with facts. Just shouting claims is simply not our style.

Ultimately, the real questions are the same for everyone:

• - What is the truth behind all the marketing noise?
• - How do I find out? What should I look for?
• - If all pumps produce water, what makes pump A 'better' than pump B?
• - Do I really need that?
• - Am I getting value for my money?

4 brands side-by-side

We have compared four 4-inch pumps with a similar duty point and similar motor (oil-filled) to ensure an apples-to-apples comparison. We chose a common duty point: +/- 4 bar pressure at a flow of 4.2 m³/h.

We didn't just pick random pumps; we looked at what is widely offered on the market and compared them to the pumps we supply. We specifically chose a popular quality pump (DAB S4 4/9) and a widely sold budget option (LEO 4XRm4/8) to give you clear insight into the differences and how they affect the price.

The candidates:

• DAB S4 4/9 - 230V 0.75kW - made in Italy
• LEO 4XRm4/8 - 230V 0.55kW - made in China
• Panelli 95 PRX 4/8 - 230V 0.75kW - made in Italy
• FKP P4 E10/08 - 230V 0.75kW - made in Italy

The pump end: Materials and specified performance

First, we look at the pump end. We see significant differences in the materials used and how the pump is constructed to handle sand, dry-running, or constant low speeds (variable frequency drives).

What can we conclude?

Sand resistance
What immediately stands out is LEO's claim of 0.25% sand resistance. For 1 m³, that means 2.5 kg of sand—which is simply nonsense. No pump with plastic impellers survives long-term if 2.5 kg of liquid sandpaper is pumped through every 1000 liters. Fortunately, LEO sellers specify a more sensible 60 gr/m³, but where that figure comes from is a mystery to us.

Panelli and FKP clearly excel here! The internal construction of these pumps is designed so that a reasonable amount of sand isn't an issue. The Panelli is the standout performer, and the use of Lexan and Noryl GFN2 makes it a wear-resistant powerhouse!

Materials
LEO uses the cheaper AISI 201 stainless steel for the housing. AISI 201 is significantly less corrosion-resistant than AISI 304, which is not ideal for a pump constantly submerged in water. Looking at the construction, you'll notice the stainless steel housing is pushed outward (the visible ridges) to thread the inlet and outlet, indicating thin-walled material. The other three brands are significantly better in this regard.

Efficiency
When looking at the pump's duty point combined with the sand resistance, it becomes clear that the efficiency of the Panelli and FKP pumps is the highest. They deliver that little bit of extra pressure, even when they have to process more sand. The build quality is simply higher, resulting in higher efficiency.

Innovation
When it comes to innovation, the FKP pump wins by a mile. The stage construction (diffuser and impeller) is superior with the addition of the ceramic bushing. It is the only pump of the four that can dry-run without issues and handle long-term low speeds (frequency drives).

The motor: Where the price difference comes from

In a borehole pump, the motor is underwater; you can't see it, but it's the most expensive part. Cheaper pumps often save on housing materials, copper winding thickness (lower efficiency), and bearings.

More of the same

Materials
LEO simply uses cheaper materials, which also reflects in its performance. This is strange, considering they have the pump with the lightest motor of the four. Something is wrong with their specified performance, but we will say more about that in a moment, as we have physically tested all four pumps.

It is noticeable that DAB also cuts corners on materials. Specifically, using nickel-plated cast iron for the upper flange and the carbon/ceramic seal is not what you expect from a renowned brand that positions itself as quality.

Efficiency
Cutting corners on materials also means saving on the thickness of the copper windings. The result is lower efficiency. The reality of lower motor efficiency is that the actual power consumed will be higher than the nominal specified motor power. M.a.w. besparen op aanschaf = meer uitgeven aan stroom.

The Practical Test

For clarity: all information above is based on the information specified by the manufacturers themselves!

LEO completely missed the mark with their sand resistance specification (perhaps we misunderstand them), but they seem to be honest about the materials used and what you can reasonably expect from the product. Now, they offer a pump with a lighter motor and lower efficiency, so the question is: does it actually achieve the specified curve? This needs testing!

There is only one solution: connect all four pumps, lower them into a well, and determine the flow using a water meter and a gate valve, then read the pressure they actually run at! Measuring is knowing! For this test, we chose several points that appear in all manufacturers' curves.

Disclaimer: we are not scientists, we have not repeated this test with multiple pumps, and the equipment used is not specially calibrated for this test (but this affects all four pumps equally). We are also biased, as we are judging our own product. We openly admit that!

A bit more? Or is it secretly a bit less?

And here is the reality check: where the three Italians pass with flying colors by consistently staying above the specified curve, the budget contender fails by consistently underperforming. While not dramatic, the cumulative effect (lower quality, lower efficiency, high energy costs) raises serious questions about R.O.I. (value for money).

The Italian borehole pumps are more expensive to buy, but they will guaranteed last longer than the LEO pump. Add the lower energy consumption (Panelli and FKP = 12% more efficient!) and you are guaranteed to spend less over the entire life cycle. Want that extra bit of innovation that handles dry-running and variable frequency drives seamlessly? Then there is only one option, the FKP borehole pump.

Our Advice

Looking for an extremely robust pump from a renowned manufacturer? Buy a Panelli 95 PRX 4/8!

Want that bit of extra innovation perfect for a variable frequency drive? Buy an FKP P4 E10/08!

Heeft u vragen over welke pomp in uw specifieke situatie het beste past? Gebruik uw gezonde verstand en bij twijfel: neem contact met ons op voor professioneel advies.