Progressive cavity pump Stator

Maintaining high efficiency and low transmission power is only possible with a perfect fit between the rotor and actuator. For this reason, a stable geometry between the two transmission elements is crucial. A calibrated magnetic core prevents significant tapering at the actuator ends.

This ensures smooth operation throughout the entire actuator length.

Typically, stators are manufactured specifically for each size and pressure stage. This custom-made stator production also enables the manufacture of stators with sealing flanges at both ends of the pipeline.

1. Product Overview

The Constant-Wall-Thickness Screw Pump Stator, also known as a rubber sleeve, is a crucial component in progressive cavity screw pumps. Its constant-wall design ensures uniform engagement with the rotor, providing high pumping efficiency, low pulsation, and extended rotor life.

Manufactured from premium elastomers such as NBR, EPDM, or FKM, the rubber sleeve is engineered to handle high-viscosity, abrasive, and chemically aggressive fluids, making it suitable for a wide range of industrial applications. Its precision-engineered geometry allows for stable flow, minimal leakage, and self-priming capability, optimizing pump performance in demanding environments.

2. Structure and Design

2.1 Design Concept

The constant-wall stator is the stationary inner lining of a screw pump, inside which the helical rotor rotates eccentrically. The constant-wall thickness provides several key advantages:

• Uniform clearance between rotor and stator, ensuring stable pumping performance.

• Reduced localized stress, extending stator and rotor life.

• Enhanced self-priming ability and high-efficiency fluid transfer.

• Compatibility with abrasive or viscous fluids, minimizing wear.

By maintaining even wall thickness, the stator delivers consistent cavity volumes, ensuring smooth, pulsation-free flow throughout the pump operation.

2.2 Components of the Rubber Stator

1. Elastomer Body:
   Made of NBR, EPDM, or FKM, it forms the sealing interface with the rotor, resisting abrasion and chemical attack.

2. Outer Casing Interface:
   Rigid or semi-rigid shell that holds the elastomer in the pump housing.

3. Inner Bore:
   Precisely molded to match the rotor profile, ensuring tight sealing and minimal leakage.

4. Constant-Wall Profile:
   Ensures uniform engagement along the rotor, reducing vibration, wear, and noise.

5. Optional Coatings:
   Special chemical or abrasion-resistant coatings can be applied for highly aggressive fluids.

2.3 Working Principle

The constant-wall-thickness rubber stator works in tandem with a helical rotor to form a series of sealed cavities. As the rotor rotates eccentrically:

1. Fluid is trapped in these cavities and progressively pushed from the suction side to the discharge side.

2. The constant-wall design ensures even pressure distribution along the rotor, minimizing backflow and energy loss.

3. The elastic nature of the rubber sleeve adapts to fluid viscosity, allowing the pump to handle slurries, viscous liquids, and particulate-laden fluids effectively.

This principle ensures consistent flow, low shear, and stable pressure, making the pump ideal for metering, dosing, and viscous fluid transfer.

3. Technical Parameters

4. Features and Advantages

1. Uniform Wall Thickness: Maintains consistent rotor engagement, reducing vibration and wear.

2. Chemical Resistance: Compatible with a wide range of chemicals, oils, and solvents.

3. Wear-Resistant: Suitable for abrasive and particulate-laden fluids.

4. Sanitary Options: FDA-compliant materials available for food and pharmaceutical use.

5. Self-Priming: Capable of pumping from dry or partially filled suction lines.

6. Energy-Efficient: Low friction and reduced leakage minimize power consumption.

7. Easy Replacement: Modular design allows quick stator swaps.

8. Versatile Application: Ideal for industrial, chemical, food, and wastewater processing.

5. Applications

5.1 Food Industry

• Transfer of honey, chocolate, peanut butter, syrups, sauces, dairy products.

• Low-shear pumping preserves texture and quality.

• Suitable for batch filling, ingredient dosing, and viscous liquid handling.

5.2 Chemical Industry

• Resins, adhesives, lubricants, polymers, paints, and coatings.

• Handles abrasive, viscous, and chemically aggressive fluids.

• Ideal for metering, batching, and chemical dosing.

5.3 Pharmaceutical and Cosmetic Industry

• Lotions, creams, gels, ointments transfer.

• Low shear preserves active ingredients.

• Compatible with CIP/SIP cleaning protocols.

5.4 Environmental and Wastewater

• Sludge transfer, filter press feeding, dewatering.

• Resistant to abrasive solids and viscous slurries.

• Ensures stable flow under demanding conditions.

5.5 Industrial Manufacturing

• Paints, inks, adhesives, sealants.

• Provides consistent flow for dosing and batching.

• Reduces rotor wear in abrasive environments.

6. Installation and Operating Instructions

6.1 Installation

1. Clean pump housing thoroughly.

2. Inspect rotor for wear or damage.

3. Align stator carefully with the rotor.

4. Press-fit, clamp, or secure stator per manufacturer specifications.

5. Verify rotor alignment and clearance to prevent premature wear.

6.2 Operation

• Start pump at low speed and gradually increase.

• Monitor pressure, temperature, and flow.

• Avoid dry running, as it can damage the elastomer.

• For high-viscosity or abrasive fluids, ensure proper feed rate and lubrication.

6.3 Shutdown

• Gradually stop the pump.

• Flush stator with a compatible cleaning fluid.

• Inspect stator and rotor for wear.

7. Maintenance and Cleaning

• Daily: Flush with water or cleaning solution; wipe exterior.

• Periodic: Inspect wall thickness, hardness, and surface integrity.

• Replacement: Replace if tears, cracks, or excessive wear are observed.

• Tips: Avoid sharp tools during cleaning to prevent elastomer damage.

8. Troubleshooting Guide

9. Safety Precautions

• Wear gloves and eye protection during handling.

• Do not exceed recommended operating temperature.

• Avoid dry running; always maintain fluid in the pump.

• Follow manufacturer guidelines for installation, maintenance, and operation.

10. Advantages Summary

• Long Life: Durable elastomer withstands abrasion and chemicals.

• Consistent Flow: Constant-wall thickness ensures uniform cavity volume.

• Versatile Application: Suitable for food, chemical, pharmaceutical, and industrial fluids.

• Easy Maintenance: Modular and replaceable.

• Energy Efficient: Low friction and reduced leakage.

11. Frequently Asked Questions (FAQ)

Q1. Maximum operating temperature?
A1. Standard: -20°C to 120°C depending on elastomer.

Q2. Can it handle abrasive fluids?
A2. Yes, designed for slurries, particulates, and viscous liquids.

Q3. Life expectancy?
A3. Typically 6–36 months, depending on application and fluid type.

Q4. Is it suitable for food applications?
A4. Yes, FDA-approved elastomers are available.

Q5. Can it be used with high-viscosity fluids?
A5. Yes, compatible with viscosities up to 500,000 mPa·s.

Q6. How to replace the stator?
A6. Align rotor and housing, press-fit or clamp the new stator, verify alignment, and start gradually.

12. Conclusion

The Constant-Wall-Thickness Screw Pump Stator / Rubber Sleeve is a vital component for maintaining efficient, reliable, and precise operation in progressive cavity pumps. Its uniform wall thickness, chemical resistance, and durable elastomer construction make it suitable for industrial, chemical, food, and pharmaceutical applications.

With features such as self-priming, low pulsation, easy maintenance, and energy efficiency, it ensures stable flow and extended rotor life, reducing operational costs and downtime. Available in customized sizes and materials, this stator is a premium solution for modern screw pump systems, handling viscous, abrasive, and sensitive fluids safely and efficiently.