There are two broad categories of industrial pumps: 1) sealed pumps and 2) seal-less magnetic drive pumps.
Sealed pumps are generally used because of a lack of knowledge regarding magnetic drive pumps.
Some important points for mechanical seal pumps Vs sealless pumps:
Sealing off the fluid being pumped: In sealed pumps, there is a mechanical seal that prevents fluid leakage while the pump is operating. However, some fluid will always leak through the mechanical seal for lubrication and cooling purposes. Some seals can be cooled by external fluids. In magnetic drive pumps, no mechanical seal is required. There is a containment shell on the pump’s liquid end that forms a completely sealed enclosure, so fluid being pumped cannot leak through. Therefore magnetic drive pumps are sealless, zero leakage pumps.
Wearing down the seal and maintenance: In a mechanical seal, there is constant movement between parts that are in contact with each other. Over time, the sealing faces and elastomers wear out, thereby resulting in increasing leakages which necessitate replacing the seals. But since magnetic drive pumps contain no seals, and therefore no need for replacements, much less maintenance is required for seal-less magnetic drive pumps.
Design of pump driving: In traditional sealed pumps, there is a coupling between the driving motor and the driven pump shafts that transfer’s power to the impeller. This arrangement makes it possible to replace the seal easily as required. But in magnetic drive pumps, the drive shaft is surrounded by a set of magnets. When the drive shaft rotates, it transfers magnetic force to magnets imbedded into the back of the impeller assembly. Therefore, there is no opening through which fluid can leak through in magnetic drive pumps, given a completely sealed enclosure in containing the fluid.
Application of fluid types being pumped: Although pumps with mechanical seals can be utilised for pumping hazardous fluids, some fluid leakage will always occur. Due to the inherent design of magnetic drive pumps, zero leakage of pumped fluids ensures they are highly reliable for pumping hazardous, corrosive, aggressive, crystalline, expensive and high purity fluids. The internal parts of magnetic drive pumps are made from non-metallic components which offer additional outstanding corrosion resistance.