Multistage centrifugal pump
Several impellers sit in series on one shaft. Each stage adds part of the head, so a higher head needs more stages, more close clearances and a longer rotor.
Pump Comparison
Pitot Tube Pump vs Multistage Centrifugal Pump
For high head at a low flow, both pump types can do the job. They build pressure in different ways, which changes the wear parts, the seal duty and the running cost. Here is how they compare, and what EHIK’s replacement projects recorded.
Two Ways to Build Pressure
One Stage or Many.
The difference in design explains most of the differences in wear, sealing and control.
Pitot tube pump
A rotating casing spins the liquid, and a stationary pickup tube turns its speed into pressure. One stage gives the full head, up to 1,050 m (3,445 ft) in the standard range.
Side by Side
How the Two Designs Compare.
The main design differences at a glance.
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| Feature | EHIK pitot tube pump | Multistage centrifugal pump |
|---|---|---|
| Stages | One stage for the full head | Several stages in series; the head rises with the number of stages |
| Main wear points | Pickup tube, rotor, mechanical seal and bearings | Impellers, wear rings, interstage bushings, balancing device, seals and bearings |
| Shaft seal | One mechanical seal at the low-pressure inlet | One or two shaft seals; the pressure they see depends on the design and the balancing arrangement |
| Axial thrust | Low; the load comes mainly from the inlet pressure | Needs a balance drum, balance disc or opposed impellers |
| Low-flow operation | Built for low flow; the minimum continuous flow of the model is confirmed at selection | At very low flow, it can run far from its best efficiency point, with more recirculation, heat and vibration |
| Flow range | Standard 0.05–70 m³/h (approx. 0.22–308 US gpm); up to 100 m³/h (approx. 440 US gpm) after engineering review | Also available for much larger flows |
| Liquid viscosity | Below 95 mPa·s (95 cP) | Efficiency falls as viscosity rises |
Recorded Replacement Results
What Changed After the Replacement.
Multistage pumps that EHIK pumps replaced, with the results from each project record.
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| Project | Change | Recorded result |
|---|---|---|
| Kong 6 Well, Shunan Gas Mine · 2015 | Motor rating 90 kW (approx. 121 hp) to 45 kW (approx. 60 hp) | 39.5% less electricity for the same volume of gas-field water |
| Wei 001-H1 Well, Shunan Gas Mine · 2014 | Motor rating 90 kW (approx. 121 hp) to 45 kW (approx. 60 hp) | 23.5% less electricity per cubic metre (approx. 264 US gal) of gas-field water |
| Jing 4 Central Station, Shunan Gas Mine | Multistage pump replaced | 48.3% less electricity per 10,000 m³ (approx. 2.64 million US gal) of water |
| Bao 46 Well, Shunan Gas Mine | Motor rating 75 kW (approx. 101 hp) to 45 kW (approx. 60 hp) | A smaller motor for the same duty |
| Daqing methanol workshop · 2009 | Motor rating 30 kW (approx. 40 hp) to 15 kW (approx. 20 hp) | Stable delivery after severe cavitation and loss of prime |
| Daqing synthetic ammonia workshop · 2010 | 75 kW (approx. 101 hp) multistage pump replaced | More than RMB 200,000 a year saved in electricity |
Energy results are from site meter readings at each project.
See the Shunan Gas Mine replacements ↗Reasons for a Replacement
Why Plants Replace a Multistage Pump.
These are the problems customers most often brought to EHIK.
Frequent maintenance
Worn stages, clearances and seals mean repeated overhauls and downtime.
Leakage and falling pressure
As parts wear, the pump starts to leak and can no longer hold the required pressure.
High energy use at low flow
A large multistage pump working at a small flow wastes power. The Shunan projects above show what a replacement recorded.
Cavitation and loss of prime
At the Daqing methanol workshop, the old pump often lost prime; the EHIK pump restored stable delivery.
A Fair Comparison
When a Multistage Pump Is Still the Better Choice.
Choose the pump that fits the duty.
Larger flows
Above about 70–100 m³/h (approx. 308–440 US gpm), a multistage pump is usually the better fit.
Lower heads
The smallest EHIK series starts at about 40 m (approx. 131 ft) of head. Below that, a standard centrifugal pump is enough.
Viscous liquids
At 95 mPa·s (95 cP) or higher, the liquid is outside the pitot tube pump range. Consider a positive displacement pump.
Replacement FAQs
Planning the Change.
Send the liquid properties, pressure and flow. NPSHa, inlet pressure and discharge pressure make the proposal more accurate.
How much electricity can a replacement save?
At Shunan Gas Mine, replacements recorded 23.5%, 39.5% and 48.3% less electricity. For your site, EHIK compares measured power, volume pumped and running hours at the same duty.
Can the new pump connect to my existing piping?
Yes. EHIK can make the pump flanges to match your existing piping, so the new pump connects to it. So far, every EHIK replacement project has matched the customer’s piping. The baseplate and drive are confirmed on site.
How efficient is a pitot tube pump?
Peak efficiency depends on the model. In EHIK’s model tables it ranges from about 38% to 65%. Compare the two pumps at your actual duty, where a large multistage pump may be far from its best point.
How fast do I get a proposal?
We reply within 1 business day. After we receive your operating data, we send a quotation and technical proposal for a pump or pump set within 3 business days.
Replacing a Multistage Pump?
Send Us Your Duty. We Will Compare.
Tell us the liquid, flow and pressure, and what goes wrong with the current pump. EHIK checks whether a pitot tube pump fits and what it would change.
Discuss a ReplacementSelection & Performance Curves
A proposed pump matched to the required liquid duty.
Outline Drawings
Equipment dimensions for checking the layout and connections.
Technical Support
Help with operating conditions, the proposed pump and supply scope.