ZW Series Self-Priming Wastewater Pump
A self-priming sewage pump that combines self-priming with anti-clogging duty, covering 5-800 m³/h at heads of 14-80 m with motor power from 2.2 kW to 55 kW.
The ZW series combines self-priming with non-clogging sewage discharge in one casing, so it can move liquids that carry large particles and long-fibre impurities. Published performance is 5-800 m³/h at heads of 14-80 m with motor ratings of 2.2-55 kW, covering industrial wastewater, municipal sewage and construction dewatering. The pump body carries a liquid storage cavity, a reflux hole and a circulation hole to form an axial recirculation external mixing system, which pulls a vacuum quickly at start-up. Because of that arrangement the pump needs neither a foot valve nor pre-filling before start-up, unlike a conventional self-priming water pump. The open impeller is shaped for anti-clogging performance, so fibrous material and larger solids pass through instead of blocking the passage.
| Parameter | Specification |
| Flow rate | 5-800 m³/h |
| Head | 14-80 m |
| Motor power | 2.2-55 kW |
| Pump type | Self-priming sewage centrifugal, single-stage |
| Speed | 1450 / 2900 r/min (by model) |
| Cavitation allowance | 2.0-5.5 m (published per model) |
| Impeller | Open, anti-clogging design |
| Priming | Self-priming by axial recirculation external mixing |
| Start-up | No foot valve and no pre-filling required |
The table lists the published ZW models with rated flow, head, motor power, speed and cavitation allowance. Larger sizes extend the range to 800 m³/h.
| Model | Flow (m³/h) | Head (m) | Power (kW) | Speed (r/min) | Cavitation allowance (m) |
| 25ZW8-15 | 8 | 15 | 2.2 | 2900 | 2.0 |
| 32ZW5-20 | 5 | 20 | 2.2 | 2900 | 2.5 |
| 32ZW10-20 | 10 | 20 | 2.2 | 2900 | 2.5 |
| 40ZW10-20 | 10 | 20 | 2.2 | 2900 | 2.5 |
| 40ZW15-30 | 15 | 30 | 3 | 2900 | 2.5 |
| 40ZW20-15 | 20 | 15 | 2.2 | 2900 | 2.5 |
| 50ZW10-20 | 10 | 20 | 2.2 | 2900 | 2.5 |
| 50ZW20-12 | 20 | 12 | 2.2 | 2900 | 2.5 |
| 50ZW15-30 | 15 | 30 | 3 | 2900 | 2.5 |
| 50ZW20-35 | 20 | 35 | 5.5 | 2900 | 2.5 |
| 65ZW30-18 | 30 | 18 | 4 | 1450 | 2.5 |
| 65ZW25-30 | 25 | 30 | 5.5 | 2900 | 3.0 |
| 65ZW25-40 | 25 | 40 | 7.5 | 2900 | 3.0 |
| 65ZW40-25 | 40 | 25 | 7.5 | 2900 | 3.0 |
| 80ZW40-16 | 40 | 16 | 4 | 1450 | 3.0 |
| 80ZW40-25 | 40 | 25 | 7.5 | 2900 | 3.0 |
| 80ZW65-25 | 65 | 25 | 7.5 | 2900 | 5.5 |
| 80ZW80-35 | 80 | 35 | 15 | 2900 | 5.5 |
| 80ZW80-45 | 80 | 45 | 22 | 2900 | 5.5 |
| 100ZW100-15 | 100 | 15 | 7.5 | 1450 | 5.5 |
| 100ZW100-20 | 100 | 20 | 11 | 1450 | 5.5 |
| 100ZW100-30 | 100 | 30 | 22 | 2900 | 5.5 |
| 125ZW120-20 | 120 | 20 | 15 | 1450 | 5.5 |
| 150ZW200-15 | 200 | 15 | 15 | 1450 | 5.5 |
| 150ZW200-20 | 200 | 20 | 22 | 1450 | 5.5 |
| Item | Detail |
| Impeller | Open anti-clogging design that passes fibrous material and larger solids |
| Casing internals | Liquid storage cavity, reflux hole and circulation hole forming the external mixing system |
| Shaft and impeller balance | Concentric shaft with a dynamically balanced impeller for vibration-free running |
| Shaft seal | Seal selected to suit the wastewater being handled |
| Drive | Coupled electric motor mounted with the pump on a common base |
| Installation | Self-priming layout removes the need for a foot valve and for pre-filling |
- Wastewater treatment plants: Moves screened sewage and sludge between process stages.
- Chemical and petrochemical works: Transfers process wastewater containing fibres and solids.
- Municipal drainage: Empties public facilities, ponds and river aquaculture basins.
- Construction sites: Dewaters pits carrying silt, stones and other construction debris.
- Papermaking, fibre and textile plants: Handles pulp, fibre and textile wastewater.
- Farmland irrigation and drainage: Pumps silty water for irrigation and field drainage.
- Check the particle size in the liquid against the open impeller's non-clogging capability before choosing a model.
- Confirm the required head falls inside 14-80 m and that the motor rating leaves margin over the duty shaft power.
- Compare the published cavitation allowance with the suction conditions on site, since sewage pumps often work with a positive suction lift.
- Choose the 1450 r/min models where solids are heavy, because the lower speed reduces wear on the impeller.
- Decide whether you need the pump as a bare unit or on a baseplate with a motor, and confirm voltage and frequency.
What makes the ZW pump self-priming without a foot valve?
The casing holds a liquid reservoir and uses an axial recirculation external mixing system. At start-up the returning liquid mixes with air drawn from the suction line and re-primes the impeller, so no foot valve or pre-filling is needed.
What size of solids can a ZW sewage pump pass?
The open, anti-clogging impeller is designed for wastewater containing larger solid particles and fibrous materials. State the maximum particle size and fibre content so the impeller and passage can be confirmed for your duty.
Which ZW model suits a construction site dewatering duty?
Start from the flow and head you need, then check the cavitation allowance. Models such as 65ZW40-25 or 80ZW80-35 cover typical pit dewatering at flows from 40 to 80 m³/h.
What is the ZW series pump used for?
It handles wastewater and sewage that carry solids and fibres, in chemical, petrochemical, mining, papermaking, textile, food and power plants, in municipal drainage and on construction sites.
Does the ZW pump need a foot valve or priming?
No. The external mixing self-priming system means the pump does not need a foot valve and does not need pre-filling before start-up.
What flow and head does the ZW series cover?
The series spans 5-800 m³/h at heads of 14-80 m, with motor power from 2.2 kW to 55 kW.
How does the ZW pump avoid clogging?
A unique open impeller and anti-clogging passage design let larger solid particles, fibrous material and other impurities pass through the pump.
What information is needed for a ZW pump selection?
Flow, head, suction conditions, maximum particle size, fibre content, liquid temperature and solids concentration, plus voltage and frequency.
Related Products
- ZX Series Self-Priming Centrifugal Pump
- IS Series End-Suction Centrifugal Pump
- CDL Series Vertical Multistage Centrifugal Pump
How to Choose the Right ZW Series Self-Priming Wastewater Pump
Quick answer: The ZW Series Self-Priming Wastewater Pump covers flow 5-800 m³/h, heads of 14-80 m, motor power 2.2-55 kW. Selection starts from the duty point - flow, head, liquid properties and available NPSH - rather than from the catalogue maxima.
Industry Applications
Explore how this equipment can be applied in related industrial sectors and review application-specific selection guidance.