Selecting a magnetic gear pump based on fluid viscosity

Introduction

The choice of an industrial pump directly affects the stability of the technological process, the accuracy of delivery, and the service life of the equipment. One of the key parameters in selection is the viscosity of the working fluid.

An incorrect pump selection can lead to reduced performance, overheating, increased wear, and unstable system operation.

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1. What is fluid viscosity

Viscosity is a physical characteristic that defines a fluid's resistance to flow.

• Low viscosity: water, alcohols, solvents
• Medium viscosity: oils, chemical solutions
• High viscosity: resins, adhesives, thick technical fluids

The higher the viscosity, the more effort is required to pump the fluid.

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2. Impact of viscosity on magnetic gear pump operation

A magnetic gear pump operates by transmitting torque through a magnetic coupling without mechanical contact.

When fluid viscosity increases:

• the load on the drive increases
• a reduction in rotational speed is required
• energy consumption increases
• the risk of overheating increases with improper selection

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3. Pump selection by viscosity level

Low viscosity (1–10 cP)

Examples: water, solvents, alcohols
Recommended series: IG series
Features: high dosing accuracy, stable flow at high speeds

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Medium viscosity (10–200 cP)

Examples: oils, chemical solutions
Recommended series: IGR series
Features: balance of power and precision, load resistance

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High viscosity (200–1000 cP)

Examples: lubricating oils, polymers
Recommended series: MG series
Features: reinforced design, stable operation under load

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Very high viscosity (1000+ cP)

Examples: resins, adhesives, thick pastes
Recommended series: MGH / MGS series
Features: high torque, increased wear resistance, operation in harsh conditions

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4. Typical pump selection errors

Using a pump with insufficient torque for high-viscosity fluids
Ignoring the effect of temperature on viscosity
Operating at excessively high speeds
Incorrect selection of housing materials and seals

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5. Materials and chemical compatibility

In addition to viscosity, it is important to consider the chemical properties of the medium:

• 316L — universal industrial application
• PEEK — high chemical resistance
• PTFE — for aggressive media
• FFKM — extreme operating conditions

Proper material selection increases equipment life and reduces the risk of accidents.

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6. Recommendations for proper selection

For accurate pump selection, it is necessary to consider:

• fluid viscosity
• medium temperature
• chemical composition
• required flow rate (L/min)
• system pressure

These parameters allow for the selection of the optimal model for a specific technological process.

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7. Conclusion

The selection of a magnetic gear pump should be based primarily on fluid viscosity and operating conditions.

The IG, IGR, MG, and MGH series cover a wide range of tasks – from precise dosing to pumping highly viscous and aggressive media.

If equipment selection is required, Macxi specialists will help choose the optimal solution for your specific process.