What is the difference between magnetic drive pumps and shielded pumps?

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Magnetic pumps and shielded pumps each have their advantages, and they serve different functions in various operating conditions. Today, let’s talk about the differences between magnetic pump and shielded pump: 1. The shielded pump makes use of the principle of electric motors directly, whereas in a magnetic pump, the energy consumed by the motor is transmitted to the impeller through the inner and outer magnets (part of this energy is converted into heat in the magnets). Therefore, theoretically, the efficiency of the shielded pump is slightly higher than that of the magnetic pump. 2. Structurally, the biggest drawback of screen pump is its inability to be repaired (it’s very difficult); whether there are problems with the pump body or the motor during use, users are basically unable to carry out repairs on their own. Repairing magnetic pump is not much different from repairing ordinary pumps. The motor bearings of shielded pumps come into contact with the medium, which makes daily maintenance as well as repairs difficult. Their reliability cannot be guaranteed, and potential problems during operation cannot be detected; once issues arise, they can cause catastrophic damage. 3. The thickness of the isolation sleeve in magnetic pump is more than 3 times that of conventional pumps, thus ensuring better sealing performance and reliability for magnetic pumps. 4. The bearings of the pump motor are lubricated by the medium; the motor does not have a fan, and its heat dissipation is achieved through the internal circulation of the medium to carry away heat. This results in a higher failure rate for such motors. The motor of a magnetic pump is a standard motor that relies on a fan for cooling, offering reliability and maturity. But this also results in the magnetic pump generating relatively high noise. 5. The structure of the screen pump is more compact, allowing it to be smaller in size than magnetic pumps and thus saving space. 6. Shielded pumps do not have couplings; magnetic pumps, on the other hand, are connected to the motor via couplings, which requires alignment. 7. Due to the use of magnetic materials, magnetic pumps can achieve a lower maximum power level compared to shielded pumps, which limits their use in applications that require high flow rates and high pressures and thus involve heavy loads. 8. Magnetic drive pumps are more suitable for highly corrosive media than canned pumps, as the isolation sleeve of magnetic drive pumps is thicker (making the isolation sleeve of canned pumps thicker would affect the electromagnetic effects between the stator and rotor windings). 9. Magnetic pumps cannot be used in situations where the medium contains metal particles (such as iron shavings), as ferromagnetic materials will be attracted to the magnets, causing failures. And the screen pump can handle it. Which is better, a magnetic pump or a shielded pump? In summary, the choice of pump type depends on how one evaluates the various options. ①If only the purchase cost (initial investment cost) is low, use a diaphragm pump. If future usage and maintenance costs are taken into account, it is recommended to use a magnetic pump. ②Additionally, if the corrosivity is particularly high, it is recommended to use a magnetic pump. If it contains particles (especially metal ferromagnetic particles), a shielding pump should still be used. ③If high process reliability is required and the medium is highly dangerous with no leakage allowed, magnetic pumps are safer.