Comparison of STING and IBO pumps – which to choose
Comparison of STING and IBO pumps – what to choose
When choosing a submersible pump for a well or borehole, the Slovak and Czech markets have long relied on two brands that have become synonymous with reliable domestic pumping solutions – STING and IBO. Both companies have decades of production experience behind them, both offer a wide range of submersible and surface pumps, and both are commonly installed in 2", 3", and 4" diameter wells. The question "STING or IBO?" comes up in almost every consultation when a customer is dealing with a new borehole, replacing an old pump, or modernizing a home water supply system. In this article, we will look at specific technical differences and construction solutions, where it makes sense to choose one or the other brand, and we will also include practical experience from typical customer orders.
Before we get into the actual comparison, it is important to note that both manufacturers are not limited to just one type of pump – their portfolios include screw (progressive) pumps for narrow boreholes, centrifugal multi-stage pumps, and combinations with frequency regulators. Therefore, the comparison "STING vs. IBO" is not a comparison of two specific products, but rather a comparison of two production philosophies and two typical series that partially overlap and partially complement each other.
Basic overview – what each brand represents
STING is a brand known in Central Europe mainly for its screw (progressive) pumps designed for narrow boreholes with a diameter as small as 2". This type of pump operates on the principle of a rotating screw in a flexible stator made of elastomer, which allows it to pump water with a higher content of mechanical impurities or sand without the pump wearing out quickly. STING pumps are characterized by a robust construction, simple maintenance, and deliberately low motor speeds, which extend their lifespan.
IBO is an Italian-Slovenian (or Central European) brand that, on the contrary, is best known for its centrifugal multi-stage submersible pumps with diameters of 3" and 4", but also has smaller models for 2" boreholes. IBO pumps are typically high-speed (2,900 – 2,950 rpm), with multi-stage impellers made of stainless steel or technical plastic (noryl), which provide higher flow rates at lower pressures and are suitable mainly for cleaner water without a significant amount of sand.
Simplified: STING = slow-speed screw pump, robust, resistant to impurities, lower flow. IBO = high-speed centrifugal pump, higher flow, more sensitive to abrasive particles, but often "more for less money" in clean water.
Schematic – principle of screw pump (STING) vs. centrifugal pump (IBO)
Construction differences and materials
In STING pumps, the key component is the elastomer stator (nitrile or EPDM rubber), in which a metal screw (rotor), usually made of stainless steel or chrome steel, rotates. This principle is derived from industrial eccentric screw pumps and its main advantage is that water is "pushed" through the cavities between the stator and rotor, not sprayed at high speeds – the pump is thus significantly more tolerant to sand, silt, and small impurities, which are common in wells and especially in older boreholes. The disadvantage is that the elastomer stator is a consumable part and it burns out very quickly when the pump runs dry (without water) – this is probably the most common cause of complaints about screw pumps in general. STING also has a model specifically designed for narrow boreholes with a diameter of 2" in its range, which is a typical representative of this philosophy – you can find it as Submersible screw pump for narrow borehole STING 2". This type of pump has proven itself especially in cases where the borehole is narrow, deep, and the water contains a slight amount of sand or silt – a classic case of drilled wells in rural areas, where the driller did not achieve a completely clean output.
In IBO pumps, the basis is a series of impellers mounted on one shaft, driven by an asynchronous motor with high speeds. The impellers are usually made of technical plastic (noryl) in the cheaper models, or of stainless steel in more durable and expensive models. The advantage of high speeds is clear – for the same pump diameter, you achieve a higher flow rate and higher head, the pump is more compact and lighter. The disadvantage is greater sensitivity to abrasive particles in the water – sand at high speeds acts like sandpaper and gradually damages the bearings, seals, and even the impellers themselves. A typical representative of this construction in the range is Submersible pump IBO 3" STM 20, which is suitable for 3" boreholes with cleaner water and where a higher flow rate is required for household or garden supply.
Comparison table of main features
| Parameter | STING (screw) | IBO (centrifugal) |
|---|---|---|
| Pumping principle | Eccentric screw in an elastomer stator | Multi-stage impellers |
| Motor speed | low, approx. 1,400 – 2,800 rpm depending on the model | high, approx. 2,900 rpm |
| Tolerance to sand | high, up to approx. 2–5 g/l depending on the model | low to medium, ideally under 50 mg/l |
| Risk of running dry | high, stators burn out quickly | medium, but damage is slower |
| Borehole diameter | from 2" | from 2", typically 3" and 4" |
| Flow rate at the same power | lower | higher |
| Head | medium, more uniform characteristic | high, sharply decreasing characteristic |
| Maintenance | stator replacement, simple | bearing/seal replacement, more complex |
| Typical price | slightly higher at the same flow rate | often more cost-effective at the same flow rate |
Borehole diameter and its influence on selection
Borehole diameter is one of the first criteria that determines whether you choose STING or IBO, simply because not every model physically fits into every well. Boreholes with a diameter of 2" (approx. 50 mm) are extremely narrow and only specialized screw pumps fit into them – here, STING dominates, because its design allows reducing the pump body diameter without a significant loss of performance. In 3" boreholes (approx. 76 mm), space is already available for IBO centrifugal pumps, which offer higher flow rates in this diameter. In 4" boreholes (approx. 100 mm), both manufacturers have a rich range and the decision shifts more to water quality and required flow rate than to physical space.
Detailed differences between borehole diameters and how to measure the borehole correctly before purchasing a pump are discussed in a separate article "What borehole diameter do I need: the difference between 2", 3", and 4" pumps," which we recommend reading before the actual purchase to avoid the most common mistake – ordering a pump that physically does not fit into the borehole or does not have enough clearance for motor cooling.
Diagram – borehole diameter and pump options
Water quality – the most important criterion that is often underestimated
From experience with standard orders, water quality, specifically the sand and mechanical impurity content, is the most common reason why a pump lasts two years instead of ten. If the well or borehole "carries" sand, which can be easily verified, for example, by visual inspection after pumping a large amount of water into a white bucket or by a longer test pumping, a rod pump of the STING type is clearly the right choice. A centrifugal pump IBO may work without problems at first in such an environment, but sand gradually wears out the impellers, bearings, and shaft seals, and the pump eventually loses performance, starts to vibrate loudly, and finally fails.
Practical example from the field: during the implementation of a new borehole well in southern Slovakia, after two months of using a centrifugal pump, a significant pressure drop was observed in the water tank. After removing the pump, it was clearly visible that the plastic impellers were worn with smoothed edges – a classic sign of abrasive wear from sand. After replacing it with a rod pump STING, the problem was resolved, as this type of construction allows sand to pass through the flexible stator without crushing it at high speeds.
On the other hand, with clean groundwater from a deeper artesian borehole, where sand is minimal or non-existent, a centrifugal pump IBO is clearly more advantageous – you achieve a higher flow rate with lower energy consumption and a lower purchase price compared to a rod pump of similar performance.
With a higher sand content in the pumped water, we recommend adding a mechanical filtration system at the outlet, for example, Sand separator 1" for suction, which will capture residual mechanical impurities before entering the water tank or the house's piping system and extend the life of the entire system, including batteries, valves, and appliances such as the washing machine or water heater.
Flow rate, head, and how to choose the performance
When deciding between STING and IBO, it is not only about the type of construction, but also about the specific performance point – that is, the combination of flow rate (l/min or m³/h) and head (m) that the pump can generate. Rod pumps STING typically have a flatter characteristic – the flow rate does not drop as significantly with increasing head, which is advantageous for deeper wells with variable water levels. Centrifugal pumps IBO, on the other hand, have a characteristic that drops more rapidly – they provide a high flow rate at low head, but the flow rate decreases relatively quickly with increasing head.
This has a practical consequence: if you have a well with a water level at a greater depth (for example, 40–60 m) and you need to pump the water to a house located at a higher elevation or to a water tank in a basement, it may be worthwhile to first look at the performance curves of a specific model, not just at the "rated" maximum flow rate. A detailed procedure for correctly calculating the required head, including friction losses in the piping, is described in the article "What performance and head to choose for a pump according to the well depth."
Diagram – typical performance curve of a rod pump vs. a centrifugal pump
Installation and operational specifications
From an installation perspective, both types of pumps are essentially similar – they are suspended on stainless steel rope or steel cable, the electrical cable runs parallel and is fixed with straps, and the discharge is either done via PE pipe with appropriate fittings or directly via threaded connection in smaller models. A detailed step-by-step installation procedure, including recommendations for cable protection, suspension method, and placing the pump above the bottom of the borehole, can be found in the article "Installation of a submersible pump in a well or narrow borehole."
The difference lies in sensitivity to dry running (without water). Rod pumps STING are significantly more sensitive to this condition – the elastomeric stator overheats and deforms within seconds to tens of seconds when running dry, which is an irreversible damage requiring stator replacement. Therefore, for STING pumps, it is always recommended to install a float switch or electronic dry-run protection that turns off the pump before the water level drops below the pump's suction part. Dry running is also undesirable for centrifugal pumps IBO and reduces the lifespan of bearings and seals, but it does not result in immediate catastrophic damage as with the stator – the pump usually "survives" a short water outage without immediate failure, although repeated occurrences significantly shorten its lifespan.
Diagram – pump placement in the borehole and dry-run protection
Price, availability of spare parts, and service
Price-wise, STING and IBO pumps fall into similar categories, with the rod pump STING being slightly more expensive at a comparable performance point – this is the cost of a more robust construction and resistance to impurities. IBO pumps are often more cost-effective in terms of price/performance when dealing with clean water and a higher required flow rate. In terms of service and spare parts, both brands are well established in the Slovak market, so you do not need to worry that in a few years you will not be able to find a replacement stator, impeller, or seal.
With helical rotor pumps, maintenance is simpler in the sense that replacing the stator is a relatively quick operation that can be handled by a more experienced DIY enthusiast with standard tools. With the multi-stage centrifugal pumps IBO, maintenance is somewhat more demanding, as it is necessary to disassemble the entire stack of impellers, properly seat the seals, and reassemble in the original order – here it is advisable to entrust the work to a professional service, especially with more expensive models with stainless steel impellers.
When to choose STING and when IBO – practical summary
If we were to summarize it into a simple decision rule that we use during regular consultations with customers:
- Choose STING if you have a narrow borehole (2" or 3"), the water contains sand or silt, the well is old with an unknown condition of equipment, or you need a more uniform flow at greater depth level differences.
- Choose IBO if you have a 3" or 4" borehole with clearly clean water, you need a higher flow at a reasonable price, you plan to supply a larger household or garden irrigation, and you want a more compact and lighter pump.
- Consider a combination – a centrifugal IBO pump supplemented with a sand separator at the outlet, which partially eliminates the risk of wear from sand, although with a high sand content this solution will never replace the suitability of a helical rotor pump.
It is also worth remembering that when deciding between submersible and surface pumps in general, i.e. even before the actual brand selection, it is advisable to read the article Submersible vs. surface pump for well water: what is more cost-effective, as in some cases (for example, a very shallow well up to 7-8 m) a surface pump may be more advantageous regardless of the brand.
Most common mistakes in selection and how to avoid them
Over the years, several typical mistakes have repeated in practice, leading to premature pump failure regardless of the brand. The first is underestimating the borehole diameter – the customer orders the pump according to the pipe diameter instead of the actual inner diameter of the casing pipe, the pump does not fit or does not have enough clearance around the housing for motor cooling. The second mistake is the absence of dry-run protection, especially with helical rotor pumps, which leads to immediate stator damage already after the first water outage. The third mistake is incorrect estimation of sand content in the water – the customer chooses a centrifugal IBO pump for its higher performance and lower price, but after a few months we have to deal with a warranty claim for worn impellers.
If you are unsure which type of pump is suitable for your specific well, we recommend reading the comprehensive guide How to choose a pump for a well: key selection criteria, or the more specific article How to choose a submersible pump for a well or borehole, where the selection process is described step by step, including the calculation of the required flow for a household.
Helical rotor vs. centrifugal from the perspective of long-term operation
From a long-term perspective, based on dozens of implemented customer projects, a simple rule applies: helical rotor pumps STING have an average longer lifespan under demanding conditions (sand, silt, fluctuating water levels), but require more thorough dry-run protection. Centrifugal pumps IBO have excellent lifespan in clean water at lower acquisition costs, but degrade faster and less predictably in contaminated water. The differences between these two pumping principles, including noise, energy consumption, and suitability for various types of wells, are discussed in detail in the article Submersible helical rotor pump vs. centrifugal – differences and applications.
An interesting practical detail is also energy consumption – at the same flow rate, helical rotor pumps usually consume slightly more electrical energy per unit of water pumped, as their mechanical efficiency at low RPM is lower than in optimized multi-stage centrifugal systems. In normal household operation (occasional pumping, not continuous operation), this difference is negligible in practice, but in the case of full-year garden irrigation or operation with high water consumption, it may be noticeable on the electricity bill.
Most common faults and service experience
With STING pumps, the most common fault is wear or burning of the stator, usually due to dry-run or long-term natural wear of the elastomer (typical stator lifespan with proper operation is 5-10 years, with improper operation even less than a year). The second most common fault is damage to the capacitor or switching unit in single-phase motors, which is externally manifested by the pump "buzzing" but not starting.
With IBO pumps, the most common faults are caused by impeller wear from sand, damage to the shaft seal (mechanical or packing seal) with subsequent water ingress into the motor, and pump blockage by limescale deposits in very hard water. A detailed overview of typical fault conditions, their symptoms, and possible solutions (including when it is worth repairing and when only replacing the entire pump is advisable) can be found in the article Most common faults of submersible pumps and how to solve them.
Frequently asked questions (FAQ)
Is a helical rotor pump STING suitable for clean water without sand?
Yes, a helical rotor pump operates reliably in clean water, but in this case you will not benefit from its main advantage over a centrifugal pump. In clean water, a centrifugal pump IBO is often more cost-effective, as it provides a higher flow at the same price.
Can a centrifugal pump IBO be used in a well with a slight sand content?
Short-term yes, but with a constant sand content, the pump's lifespan is significantly reduced. We recommend adding a sand separator to the suction in such cases and regularly checking the pump performance – a drop in flow is usually the first sign of impeller wear.
What is the price difference between comparable STING and IBO models?
At the same performance level, a helical rotor pump STING is usually 10-20% more expensive than a centrifugal pump IBO, which reflects the more robust construction and higher resistance to impurities. In the case of models for narrow 2" bores, however, the price comparison is limited by the fact that the competition in this diameter is more restricted.
Can a centrifugal pump IBO be used in a 2" borehole?
In most cases no, because multi-stage centrifugal pumps require a larger diameter to accommodate the necessary number of impellers. Therefore, helical (screw) pumps are almost exclusively used in 2" bores, such as the model Submersible helical rotor pump for narrow boreholes STING 2".
How long does the stator of a helical rotor pump last?
With proper operation (no dry-run, with an appropriate sand content in the water), the stator typically lasts 5 to 10 years. With repeated dry-run operation, it can be damaged already during the first such incident, so an automatic water shortage protection is appropriate.
Is it worth combining an IBO pump with a sand separator?
Yes, this combination is common and recommended especially with a slight sand content, when it does not make sense to invest in a more expensive helical rotor pump, but at the same time you want to protect the piping, batteries, and household appliances from mechanical impurities. A suitable addition is Sand separator 1" for suction.
Conclusion
The choice between STING and IBO is not a question of which brand is "better" in an absolute sense, but of which construction principle better suits your specific well, borehole diameter, water quality, and required flow. Helical rotor pumps STING are the first choice for narrow boreholes and contaminated water with sand content, where their robust construction can reliably serve for many years in conditions that would quickly wear out a centrifugal pump. Multi-stage centrifugal pumps IBO, on the other hand, are a cost-effective and affordable option for cleaner water and larger borehole diameters, where you will appreciate their higher flow and compactness. The full range of both brands, including other models and accessories, can be found in the category Pumps for wells, where we can help you choose a specific model according to the parameters of your well in case of any uncertainties.
Do you have a question on this topic?
Having trouble making a decision or dealing with a specific situation in your home? Write to us – we are happy to help.