Rotor and Stator (Screw Pumps)

Rotor Stator Pump FAQs

1. What are rotor stator pumps, and how do they work? 

Rotor stator pumps, also known as progressive cavity pumps or eccentric screw pumps, are a type of positive displacement pump designed for efficiently transferring viscous and abrasive fluids.

These pumps consist of two key components:

• Rotor: A spiral-shaped steel shaft that rotates inside the stator.

• Stator: A metal tube with an internally molded cavity, typically made from synthetic or natural rubber, that matches the shape of the rotor.

As the rotor turns, it creates enclosed conveying chambers with the stator. These chambers move continuously in the direction of the flow, ensuring a consistent, low-pulsation transfer of materials. The rotor's corkscrew shape and off-center rotary motion are what give this pump its alternative name, the eccentric screw pump.

This design allows for gentle handling of sensitive materials while maintaining a steady and efficient pumping process, making rotor stator pumps a preferred choice for demanding applications.

We produced a short animated video to show you the inner workings of progressive cavity pumps:

2. What are rotor stator pumps used for?

Rotor stator pumps are versatile and used across various industries due to their ability to handle a wide range of materials. Our line of rotor stators is primarily designed for Construction and Refractory applications. Putzparts specializes in rotor stators designed for pumping liquid screed, mortar, grout, gypcrete (self levelling underlayment), plaster/stucco and fireproofing cement, ensuring efficient and reliable material transport on construction sites. 3D Concrete Printing is a new and exciting industry that values progressive cavity pumps for their continuous flow. 

3. What are the relevant factors when choosing the rotor stator?

Selecting the right rotor stator is crucial for achieving optimal performance and efficiency. Key factors to consider include:

• Size and Diameter: The dimensions of the rotor and stator must align with the type and volume of material being pumped. 

• Material Grain Size: Coarser materials require larger diameters to prevent clogging and ensure a steady flow.

• Desired Flow Rate: The pump's design should match the required flow rate for the application.

• Pressure Stability: Different rotor stator designs influence how stable the pressure remains during operation, impacting the final pumping results.

Choosing the correct rotor stator ensures efficient pumping, reduces wear, and extends the pump's lifespan. For specialized applications, it's essential to consult with experts to match the right pump design with the material properties and operational requirements.

4. Maintenance-free or clampable rotor stators?

• Maintenance-Free: Easy to install, with unslotted steel tubes ensuring consistent pressure and minimal maintenance.

• Clampable: Adjustable for material type and grain size. Available with built-in or external clamps. Requires retightening when delivery pressure drops.

Both types support smooth, continuous pumping with minimal pulsation. The best choice depends on operational flexibility and material handling needs.

5. How to choose the right rubber for your stator?

The shore value indicates rubber hardness. Lower shore numbers mean softer rubber, which is ideal for pumping materials with sharp aggregates as it reduces wear. Harder rubber, with higher shore values, generates more pressure.

Considerations when selecting shore hardness:

• Material Type: Softer rubber is better for abrasive materials.

• Working Temperature and Climate: Rubber softens in heat. In warmer climates, harder rubber is preferred, while temperate regions may require alternating shore hardness based on seasonal changes.

Selecting the correct shore ensures durability, optimal pressure, and efficient material handling.

6. Does Putzparts supply high-quality rotor stator pumps?

Yes, Putzparts provides mostly premium-quality rotor stators, proudly made in Germany. Our rotors are crafted from high-alloy steel, never hollow, and precisely drilled for enhanced durability. The stators are made from high-endurance rubber, ensuring long-lasting, reliable performance and consistent pumping results.

This combination of precision engineering and high-quality materials guarantees dependable operation, reduced wear, and optimal efficiency in every application.

7. Can I use the pumps for different machines?

Yes, Putzparts supplies rotor stator pumps compatible with various machine brands, including Putzmeister, PFT, M-Tec, Uelzener, Turbosol, Mai, Utiform, Inotec, Imer, Brinkmann, and many more. Many machines utilize the same rotor stator types for efficiency. Different brands may require different rotor head designs. 

8. I can’t find the rotor stator I’m looking for. Can you supply different types?

Most likely, yes. We offer an extensive selection of rotor stator pumps in our shop and can provide custom series in nearly any stator size at optimal costs.

If you need assistance in finding the right product or require a custom solution, feel free to contact us. We respond promptly to inquiries and provide tailored solutions to meet your specific requirements.