Independent Testing

“Large Stelth Pump” prototype. Pressure transducers map the internal pressure zones within the pump while it is running”

The Stelth Pump has periodically been independently tested and validated.

People understandably expect testing of the Stelth Pump by independent authorities.

Preceded by many years of our own R&D and testing in our own test rigs; here’s how and when that independent testing and validation started and how it presently continues.

This website is specifically for the attention of pump manufacturers or otherwise pump literate or technical people

You do not need to interpret the Chinese Gov, ITT (Xylem) or Koller charts! They are provided for those who can or who you want to show them to and so they are immediately viewable here to support our performance claims. Also, the full reports are available; just ask.

We took prototypes of a Stelth Bilge pump, Stelth Automotive engine cooling pump and two Stelth Spa pumps, plus 3 manufactured competitor pumps to China for back to back testing.

We attended and had them tested at Leo and Dayuan pump companies and also at the “Product Quality Supervising and Inspecting Institute of Taizhou City” a Chinese Government testing lab and they delivered the following results:

Fig 1

Results for the Koller 650-watt pump from the “Product Quality Supervising and Inspecting Institute of Taizhou City” PDF report. Efficiency % is in column 6 from right. The full reports are available. Just ask us to email them.

The bottom lines are the electrical power (watts) curve. The middle lines are pressure/flow curves and the upper lines are the efficiency curves. Pressure and efficiency curves are positioned the same for all the charts in this report.

Fig 2

Test lab results from “Product Quality Supervising and Inspecting Institute of Taizhou City” for the Stelth pump using a Koller conventional induction motor.

The Koller 650 achieved a best efficiency point (BEP) of 30.65% (Fig 1) and the Stelth 650 got a BEP of 47.67% (Fig 2).

The Stelth, tested in a Chinese Gov test lab, was 55.46% more efficient than the Koller.

This validated the Stelth pump for our own aims of building upon credible and independent testing, justifying increasing effort.

It also made me confident that granting a manufacturing license to Koller was safe for them and us, in that we then knew they would not get a failure when they finally manufactured.

Now it has become the most powerful and efficient spa pump in the world and it is implicit that it will become the most powerful and efficient when applied to almost all other pumping categories. Koller Whirlpool of Austria also prove the principal, efficiency and manufacturability, because the Stelth operating principle is the same for all the industries our pump will be applied to.

The Koller “Ecolution” brochure (extract in Fig 3) can also be regarded as a report by an independent manufacturer who have tested back to back in their own test rig.

Fig 3

Here is an extract from the Koller report from their “Ecolution” brochure.

The noise column on the left is put together by persons who apparently know nothing about sound pressure levels, expressed as dBA. In fact, 9 dBA less (from the Koller noise report) for the Stelth, is 8 times quieter than same size competitor, not merely 52% quieter, as above. The other columns are correct. Koller noise report available. Ask us to email it to you.

Fig 4

Koller publish the Stelth 600-watt pump is far better than their old 800-watt pump.

Download the Koller brochure; wait a couple of minutes to download.

We also tested at the Leo Pump Company in China.

Fig 5

The chart at right is for Leo’s own 800-watt spa bath pump. Efficiency % in column 13.
It had a BEP of 34.91%.

Fig 6

Leo’s test of the Stelth 800-watt spa bath pump at BEP of 43.23%. It employed the Koller 800-watt motor.

The Stelth was 23.83% more efficient than the Leo.

The Gov test lab, “Product Quality Supervising and Inspecting Institute of Taizhou City” also tested the Rule 3700 bilge pump manufactured by ITT, now named Xylem, the world’s largest pump company. The “Rule” brand of bilge pumps are the world’s largest selling bilge pumps.

Fig 7

Stelth and ITT’s Rule 3700 bilge pumps tested by “Product Quality Supervising and Inspecting Institute of Taizhou City”. Since then the Stelth pumps are even smaller and even more efficient.

Fig 8

results for the ITT “Rule 3700”. Efficiency % in column 6 from right.

The “RULE 3700” had a Best Efficiency Point of 30.06% @4.83 cubic metres/hour and 183.6 electrical watts.

Fig 9

results for the Stelth bilge pump from same test rig. BEP was 36.98% @5.56 cubic metres/hour and 170 electrical watts. Higher flow using less electricity = lives saved at sea?

This same Stelth bilge pump interchanges as the Stelth car engine cooling pump. The much smaller Stelth bilge pump was 20.8% higher efficiency than the Rule 3700. All Chinese Gov test reports are available. Ask us to email them.

*Now a significant increase in performance. The chart of Fig 10 below, shows dramatic improvement over the chart of Fig 6 for the Stelth 800-watt pump.

Fig 10

Results at Dayuan were similar but a small amount better for the Koller 800-watt spa bath pump. The blue curves are for NFT’s latest 800-watt pump. Lower curves are the pressure curves and upper lines the efficiency curves.

Fig 11

The blue curves are for NFT’s latest 400-watt pump.

Charts of Fig 10 and Fig 11 are of NFT testing of Stelth Pumps which incorporate novel internal geometric innovations, not exclusively pump related, which now puts the combination way ahead of the older Stelth pumps and other pumps manufactured by Koller, or by any other manufacturer in that industry.

Had these geometric innovations been incorporated in the Stelth Pumps tested at Leo, Dayuan and “Product Quality Supervising and Inspecting Institute of Taizhou City”, shown in the chart of Fig 10, the BEP for the Stelth in chart of Fig 6 above, would be 52%, not 43.23% tested back then. This applies to all the older Stelth pumps tested back then but which were, never the less, significantly ahead of competitors. They were old performance, now there is the “new”.

We point out that this significant and disruptive technology is also going to revolutionise many other pump industries. Reason 1 is that the Stelth principle applies universally. One pump can be interchanged between many different industries. Example: the Stelth 800-watt pump (or any size), manufactured by Koller, goes, absolutely un-altered, into Aquaculture, general water circulation, water transfer, water features +. All these keep the same motor. Additionally, dozens of other industries will use alternative motors but the manufactured Stelth hydraulic wet end will not change. Reason 2 is that innovations recently applied to the Stelth pump also apply to all non-Stelth pumps. We want to drive these 2 points home because some people think pumps for many widely different industries are different types of pumps for each industry! Not so!

A non-exhaustive list of Stelth Pump applications is:

  • Rural/agriculture, for irrigation and transfer, driven by electric motors, internal combustion engines and also solar.

  • Marine such as Bilge, showers, kitchen sinks and fuel pumps; for virtually silent running (Stelth) for submarines and other military shipping for their showers and kitchen sinks.

  • Automotive such as; electric motor driven engine cooling pumps, fuel pumps, (bowser pumps too?).

  • Aerospace for fuel pumps, sinks, toilets etc.

  • Aeronautical for fuel pumps, sinks, toilets etc.

  • Pumping of volatile liquids and fuels due to no cavitation.

  • Factories.

  • Steel mills.

  • Dam to city dam/creek to rural dwellings/buildings.

  • Power stations.

  • High rises.

  • Municipal water mains.

  • Sewerage pumps.

  • Dishwashers.

  • Washing machines.

  • Using very high RPM motors, a single stage Stelth replaces 4 or more stage conventional pumps. Conventional pumps cannot run at Stelth higher RPM’s.

  • Pools.

  • Spas.

  • Solar pumping for agriculture with and without batteries.

Further validation by independent institutions.

We took the Stelth Bilge pump and the Stelth automotive engine cooling pump to ITT, now named Xylem, the world’s largest pump manufacturer. We also took the EWP 115 Automotive engine cooling pump made by Davies Craig so ITT could test back to back.

Fig 12

ITT (Xylem) test of the Stelth and the EWP 115. EWP means Electric Water Pump.

We are almost embarrassed by the mere 21.66% efficiency increase of the Stelth over the EWP115 but back then we were still learning.

However, this was the “old, without the novel geometric innovations” installed. Now refer to the charts of Fig 10 and Fig 11 concerning recent performance % increases incorporating those novel geometric innovations.

Early 2018 we intend to create our new Automotive engine cooling pump incorporating recent geometric innovations into the Stelth pump as reflected in Fig 10 and Fig 11.

We also took to ITT, Xylem, the world’s largest selling bilge pump, the Rule-Mate 2000 made by ITT (made by themselves).

Fig 13

Back then the Stelth bilge pump was half the height. later Stelth bilge pumps are even more squat, more efficient with higher flow and pressure. They fit under boat motors better.

Fig 14

Test, above, by ITT in their own test rig in Gloucester Massachusetts, which we attended.

The Stelth bilge pump was 40.38 % more efficient than the world’s largest selling bilge pump. Higher efficiency might mean lives saved at sea. Since then we have even higher efficiency due to the, above mentioned, novel introduced innovations.

A novel Australian, high efficiency, higher RPM electric motor has been developed with help of University of Adelaide (UA).

The “new motor” owners want to launched it powering a “product”.

The Stelth pump was chosen as that potential product and a pump testing rig was constructed at University of Adelaide.

Fig 15

The pump test rig constructed at UA.

Below are results obtained by UA for the Davies Craig automotive engine cooling pump and the Stelth auto pump.

Fig 16

2000 RPM is a reasonable conventional speed for each pump.

The University test rig has automated data collection. When a pump flow and pressure become erratic, due to incapacity to continue pumping when at too high RPM, the data collected cannot be trusted.

The Davies Craig automotive engine cooling pump (the EWP 115) showed predictable performance up until 3000 RPM. But 3500 RPM was simply too much for it and the curves for it in the chart of Fig 17 below published by UA are a meaningless scribble.

Fig 17

The curves, especially the efficiency curves bottom right for 3,500 RPM, demonstrate that conventional pumps cannot run at the higher RPM that the Stelth Pump can.

So, independent University testing at high pump speeds proved the large advantages of high speed for Stelth Pumps.

The other very important step with the University testing was that now we could have tested, for the first time, the true hydraulic performance of the Stelth “wet end”. Before that all tests were with induction motors that were usually the same motor we cannibalised off the pump we were testing against. That was very useful but otherwise with different, but same rating motors you could not be totally sure if it was the motor or the pump that was better.

The charts of Fig 16 and Fig 17 proved that the Stelth was capable of high efficiency over a very broad speed and load range. It also proved that the Stelth efficiency increases with increasing RPM. These advantages are not possible for conventional pumps e.g. the Davies Craig pump collapses with high RPM as do all conventional pumps.

Fig 18, below, is also from University of Adelaide tests.

Fig 18

Charts by UA. The Stelth Pump had a 93mm (3.66 inch) impeller. The inlet and outlet ports were too small and so was the pipe size. (40 mm pipe) hence the comment by UA about 5000 RPM being the limit. Pipes were later changed to nominal 50mm (internal diameter 53mm). It could push 350 litres a minute of water vertically more than 155 feet.

Fig 19

Green dots show where the BEP, pressure, flow and motor Kw of Fig 18 above, compare on the chart from the Dayuan multi-stage pump brochure.

The single stage Stelth pressure and flow are better than a 7 to 10 stage Dayuan vertical bore pump and with higher efficiency. That was the “old” Stelth technology.

Stelth pumps at UA have run to 7000 RPM. No data was collected at 7000RPM. The pressure at 7000 RPM would have been 618.9 kPA This is from a 93mm dia impeller! It would push 200 litres a minute vertically more than 207 feet. The University testing is how we learned we potentially had a single-stage replacement for many multi-stage pumps.

These results are what the Stelth pump has already done. They are not projections.

Below are charts from University of Adelaide tests performed with the Stelth with a 77mm (3 inch) diameter impeller. It could lift water vertically over 30 metres (over 107 feet).

Fig 20

Charts generated by the University of Adelaide. This Stelth also had a too small inlet and outlet.

Fig 18 and Fig 20 charts are for the old Stelth. Now efficiencies are higher and the RPM can be increased. Look at Fig 10 and Fig 11 again to see the possible percentage increases in performance that might be available now if incorporating the novel additions. It could, way back then, push water vertically more than 107 feet.

These University tests showed us that in the Stelth pump we had a single-stage replacement for many multi-stage pumps. It needs a high RPM motor to be able to replace many stages with one stage.

Pool Pumps

Promisingly, the Stelth pool pump, with leaf bowl, has achieved above 67 “litres per watt hour”, being the nomenclature for “energy efficiency”, tested in the NFT test rig, potentially qualifying it for 10-stars, according the Australian standard AS5102 if it becomes manufactured.

This was a prototype using a new Australian developed motor. In fact, the achievement preceded any of the pool pump manufacturers including Hayward.

Work will continue into 2018 to forge this into a manufacturable pool pump and motor combination with highest “energy efficiency”.

Recently, we had tested at CalTest in South Australia, the same Stelth 400-watt pump as is shown in the chart of Fig 11, above and an 1850 watt Stelth pump. These are not pool pumps.

The CalTest test rig is constructed according to the example in Australian Standard AS502 for pool pump testing. After adjusting for some differences between test rigs we can confirm that the results we obtain in the NFT test rig are accurate. For example, the results in Fig 10 and Fig 11 above, are correct.

Fig 21

The NFT test rig. This allows for testing of NPSH*, or for simulation of lift capability, therefore reality.

NFT test rig can have the suction side valve partially closed, imposing a negative pressure at the pump inlet, simulating reality conditions where a pool pump has to lift water. Pool pumps, due to height above water, bends and long pipes, generate any pump’s suction side negative pressure of - 9 kPA to - 10 kPA.

Net Positive Suction Head (NPSH) indicates a pumps resistance to cavitation due to poor vertical lifting. The NFT test rig can test a pump’s ability to vertically lift water. The AS5102 test rig cannot.

Fig 22

The AS5102 test rig in which the pump is always below water. NPSH cannot be tested; meaning the pump’s vertical lifting ability is never challenged.

The latest performance, due to introduction of the novel additional features demonstrated in the charts of Fig 10 and Fig 11, has been shown to be correct by adjustment of the different layout of the ASS5102 test rig and the NFT test rig. Pump literate engineers know the way to do the adjustment. Most people cannot, so we plan to take the latest pumps to a reputable testing lab, maybe CSIRO, in early 2018 so the pumps can be tested in a test rig that conforms to International testing standards. We want everyone to know we are doing our homework and not guessing or using faulty testing techniques.

Following is a test report from 2011 recently come to light.

In the following report, the term “AMM based motor” refers to the high RPM novel amorphous iron motor, the world’s highest efficiency electric motor.

However, the whole report is about the Stelth pump “wet end” results from the UA test rig which was purposely built to test the Stelth Pump to be able to match it to the motor. The conventional motors were removed from the Stelth pump and a high speed, University lab motor and Torque transducer were used to find the characteristics, including the efficiency, of the Stelth “wet end” alone, apart from any motor. The AMM motor was not used for this.

Note the reference to “net positive suction head” (NPSH). Pumps 2 and 3 are obviously the 2 Stelth pumps. Pump 1 was the Davies Craig EWP 115 automotive engine cooling pump wet end without its motor.

Recent tests on a later, improved Stelth Pump with a 77mm (3 inch) diameter impeller are at least 12% higher efficiency than those in the above University report.

As shown; NFT has periodically had Stelth pumps tested independently for our learning and also for our justification and inspiration to continue our challenging and exciting development work, helping us to focus and re-focus on the best environmental and industry targets.