PUMP SCHOOL Magnet drive pumps
What is a magnetic drive pump?
A magnetic drive pump is a type of pump driven by the force of magnetism rather than being directly coupled to a motor. Mag-drive pumps eliminate the mechanical shaft seal that conventional pumps require, and they are completely leakproof. They’re noteworthy for being one of the only types of pump that use the force of magnetism to generate movement. Magnets are mounted on a carrier or drive assembly and are driven by a standard electric motor. Mag-drive pumps are generally considered a type of centrifugal pump, although there are also some versions of positive displacement magnetic drive pumps (like gear pumps).
What are the benefits of a mag-drive pump?
The elimination of the mechanical seal, one of the largest components of pump maintenance cost, is one of the key advantages of the magnetic drive pump. This greatly reduces the initial cost of the pump as well as day-to-day operational costs as there aren’t any mechanical seals, seal-fluid pots, or cooling lines fitted. The pump is also assured to be leak free.
When would I need one?
Magnetic drive pumps have a variety of applications including pumping chemicals, hydrocarbons, and other liquids that are difficult to seal, or where the consequences of leakage are serious. Also when pumping heat transfer fluids which are high temperature or which are prone to costly evaporative losses with traditional mechanical seals. Mag-drive pumps are also recommended for all types of thin non-viscous liquids.
Key features
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The magnets are typically made of ceramic, samarium cobalt, or neodymium. Bushings and thrust surfaces inside the can are made of silicon carbide or tungsten carbide,
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or ceramic, to handle the potentially abrasive liquid that circulates inside the can. Most must be protected against loss of flow, which could seriously damage the pump due to temperature buildup due to the magnetic flux.
Selection specifications
The primary specifications to consider when selecting magnetic pumps are flowrate, pump head, pressure, horsepower, power rating, outlet diameter, and operating temperature. Consult your local pump supplier for choosing the best magnetic drive pump for you. Article courtesy of Kelair Pumps Australia “When Pump Knowledge Matters” Phone 1300 789 466, or visit www.kelairpumps.com.au.
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