Magnetic Drive Pumps
For instances where you need a pump that has no seals, doesn’t allow any fugitive emissions and will prevent leakage of fluid (or the loss of dangerous/costly fluids) you need a Magnetic Drive Pump or mag-drive-pump.
Unlike a traditional centrifugal pump, which has a direct drive connection between the impeller and motor, a magnetic drive pump (or mag-drive pump) does away with the direct drive mechanism and replaces it with a magnetic field. In a mag-drive-pump, a balanced magnetic field is used to create the rotation of the fluid impeller.
At General Pump Company, we can provide you with European designed and manufactured magnetic drive centrifugal pumps to meet your every need.
What are Magnetic Drive Pumps?
Magnetic drive pumps, also known as mag-drive pumps or magnetically coupled pumps, are a type of centrifugal pump that uses a magnetic coupling to transmit torque from the motor to the impeller without the need for a mechanical shaft seal. This design eliminates the risk of fluid leakage associated with traditional pumps, making magnetic drive pumps particularly suitable for handling hazardous, corrosive, or volatile fluids. Here’s a closer look at magnetic drive pumps and their applications:
How They Work:
In a magnetic drive pump, the motor rotates a magnet assembly, which in turn drives a second magnet assembly connected to the impeller through the pump’s casing. The magnetic coupling transfers torque from the motor to the impeller without the need for a direct mechanical connection, thereby eliminating the potential leakage path provided by a shaft seal.
Magnetic drive pumps offer a reliable and efficient solution for a wide range of industrial, commercial, and scientific applications requiring the safe handling of corrosive, hazardous, or sensitive fluids. Their leak-free design, corrosion resistance, and precise fluid control capabilities make them indispensable in industries where fluid containment, environmental protection, and process integrity are paramount.
How does a Magnetic Drive Pump Work?
While traditional centrifugal pumps use a mechanical coupling to drive the impeller or pump unit via a solid shaft and fluid coupling, a magnetic drive pump system utilises the attraction of a drive magnet and an impeller magnet to provide the coupling. Therefore magnetic drive pumps, unlike other direct drive pumps, do not require seals. Instead, the drive magnet rotates around the rear casing (housing), and the impeller has an inner magnet which is forced to spin or follow the drive magnet thereby providing the power transmission.
As the two components (drive and impeller) are physically separate units, there is no need for seals. This means makes mag-drive-pumps are leak free and means they have reduced maintenance requirements, lower lifecycle costs and meet stringent safety standard requirements. For example, if the fluid you need to transfer/convey is of a corrosive or hazardous nature, such as sulphuric acid, utilising a mag-drive pump is an ideal, safe solution.
Types of Magnetic Drive Pumps
Magnetic Drive Pumps come in two variations or types; a stationary shaft and a rotating shaft magnetic drive pump.
Stationary shaft magnetic drive pumps are ideal for light to medium duty installations. As the name implies they have fixed shafts hence are simpler in construction than the rotating shaft design. They are typically constructed from non-metallic components and consequently have excellent corrosion resistance and can operate up to 120 deg C.
Rotating shaft magnetic drive pumps are high strength units typically of metallic construction and are intended for heavy-duty applications. As they are of a robust nature they provide superior strength, hence can operate at a higher temperature and pressure rating. They are usually made of metal, which provides the best strength, temperature, and pressure ratings. They are more complex in design than stationary shaft units.
Features
Magnetic Coupling: The key feature of magnetic drive pumps is the use of a magnetic coupling to transfer torque from the motor to the impeller. This coupling consists of two sets of magnets, one attached to the motor shaft and the other to the impeller, which transmit torque through the pump’s casing without direct contact.
Hermetically Sealed: Since there is no shaft penetrating the pump’s casing, magnetic drive pumps are hermetically sealed, preventing leakage of the pumped fluid. This feature is particularly beneficial when handling hazardous, corrosive, or volatile fluids.
No Mechanical Seal: Traditional centrifugal pumps require mechanical shaft seals to prevent leakage along the shaft. In contrast, magnetic drive pumps eliminate the need for mechanical seals, reducing maintenance requirements and the risk of seal failure and fluid leakage.
Leakage Prevention: The absence of shaft seals minimizes the risk of fluid leakage, making magnetic drive pumps suitable for applications where fluid containment and environmental protection are critical, such as in chemical processing, pharmaceutical manufacturing, and semiconductor fabrication.
Corrosion Resistance: Magnetic drive pumps are often constructed from materials such as reinforced thermoplastics, ceramics, or stainless steel, which offer excellent corrosion resistance. This makes them suitable for handling aggressive chemicals and corrosive fluids without the risk of pump damage or contamination.
Efficient Operation: Magnetic drive pumps typically operate with high efficiency due to their streamlined design and the absence of friction associated with mechanical seals. This efficiency can result in energy savings and reduced operating costs over the pump’s lifecycle.
Benefits
Enhanced Safety: The hermetically sealed design of magnetic drive pumps minimizes the risk of hazardous fluid leaks, protecting both personnel and the environment from exposure to potentially harmful substances.
Reduced Maintenance: By eliminating mechanical shaft seals, magnetic drive pumps require less maintenance compared to traditional centrifugal pumps, reducing downtime and associated costs.
Longer Service Life: The absence of wear-prone mechanical seals and the reduced risk of pump damage from fluid leaks contribute to the extended service life of magnetic drive pumps, providing reliable performance over time.
Versatility: Magnetic drive pumps are suitable for a wide range of applications, including chemical processing, pharmaceutical production, water treatment, and circulation systems, due to their ability to handle various fluids and aggressive chemicals safely and efficiently.
Environmental Compliance: The containment of hazardous or toxic fluids within the pump’s sealed housing helps industries comply with environmental regulations and safety standards by minimizing the risk of fluid spills or emissions.
Applications
When considering using a magnetic drive pump for your application, you should review the following operational requirements:
Temperature: If the magnets in a mag-drive-pump overheat, they can demagnetise. When choosing a mag-drive-pump, look at the operating temperature of your application and compare this with the maximum operating temperature of the mag-drive-pump. To be safe, the maximum rated temperature of the magnetic drive pump should be at least 25 to 50 degrees higher than the operating temperature in your application.
Pump bearings and fluid transfer: The bearings on a mag-drive-shaft are lubricated by the fluid conveyed. This means that the type of fluid can directly influence the performance of the system. In instances where dry running, low liquid, suspended solids or materials that have low lubrication are involved, the mag-drive-pump operation will be impacted.
Decoupling: Decoupling takes place when the magnetic drive pump is operated beyond its maximum torque rating. If continuously utilised in this state, demagnetisation of the magnets can occur causing degradation in pumping performance. Monitoring of power consumption is recommended to ensure your mag-drive-pump is operating at its ideal torque range under variable speed conditions.
Mag-drive-pumps are primarily designed to transport clear low viscous fluids with no solid content and are therefore suitable for:
Chemical and petrochemical uses I Industrial use I Agricultural use I Mineral processing I Heat transfer fluids I Mineral processing I Filtration systems I Clean-in-place (CIP) systems I Pulp mills Power plants I Waste and wastewater treatment
Mag-drive-pumps are not recommended for applications involving slurries, sludge or other solid laden fluids.
