7 Key Factors to Consider When Selecting the Right Borehole Pump

7 Key Factors to Consider When Selecting the Right Borehole Pump

Interrupted water supply, poor water pressure, unnecessary energy consumption and excessive pump maintenance are issues that can all be expected if the wrong borehole water pump is selected for your installation. With lots of options on the market, making a decision on what model you need can be quite daunting. This is exactly why as a leading Borehole Pump supplier, Whisper Pumps have put together a handy guide to the factors you need to consider.

If you’re reading this article then you will already know that A Borehole Pump has a very specific design of a thin, vertical pump that is immersed into a drilled hole/well in the ground to extract water. Their very specific application means that there are some features that are standard amongst all submersible borehole water pumps for example being made from corrosion resistant materials such as stainless steel to prevent abrasion caused by the earth and mineral deposits. But in other ways they can vary…

1. Borehole size

Typically, you will find that most boreholes for private water supply are 4 to 6 inches in diameter, making 4 inch borehole pumps our most commonly selected models, followed by 6 inch. In some scenarios though, smaller boreholes are drilled at 3 inches. When this is the case, or where a 4 inch borehole has reduced in size due to ochre and residue deposits that have built up over time, a 3 inch Borehole Pump may be required.

2. Immersion depth

How deep a borehole is drilled into the ground depends upon the depth of the ground water level that it needs to reach. Different models of submersible borehole water pumps have different maximum immersion depths, so it is vital that the selected pump is able to efficiently operate at the water level in question.

3. Flow rate

The required flow rate of a borehole pump (this being the speed at which the water is moved) is directly affected by the demand on the water supply and what it is being used for. For example, a borehole supplying water to several domestic properties for their drinking, toilets, showers and washing will require much higher flow than one that is simply used for periodic cleaning down of equipment.

4. Pressure

By nature, borehole water pumps typically offer high pressures due to having to pump long distances vertically. However, it does need to be ensured that the selected model is able to generate the pressure required to get the water supply to where it needs to be. This depends upon the depth of the borehole to ground level and then the distance from the ground level to the final end point e.g. where the water tank is sited. The further the distance, the higher the pressure requirements of the borehole pump to prevent the water from trickling out. When it comes to both flow and pressure, it is common for a margin of safety to be added to ensure that once installed the pump does not fall short. Oversizing however is one of the largest causes of pump inefficiency resulting in unnecessary energy consumption and electricity costs, so we recommend being as accurate as you can when determining duty requirements.

5. Power supply

Check whether it is 230v or 400v electricity supply you have on site, as this is something that needs to be considered when selecting which submersible borehole pump you need for your installation.

6. Sand handling capabilities

Depending upon the location of the water source in question, there may be more sand content in the water than others. When this is the case, the borehole pump needs to be able to handle the sand without clogging or abrasion. Models with self-cleaning floating impellers are typically able to pump more g/m3 than others and should be selected.

7. Borehole pump control features

By implementing borehole pump controllers features alongside the pump, it can help private water supply feel as close as possible to getting water off the mains:

• Starter box – on/off switch
• Variable speed drive – Adjust pumps speed to the current demand on the water supply
• Overload protection - Stops pump running when experiencing voltage overload to prevent pump damage.
• Dry run protection – Stops pump running when there is a low water level to prevent burn out and pump damage.

If you’re still not sure what you need, then that’s where we come in! Our technical sales engineers have been specifying borehole pumps to borehole drillers, water engineering companies as well as owners of private water systems themselves for the best part of 25 years. Simply give us a call on 01777 871100 and we will advise you on the borehole water pump that best suits your installation.