Corrosion resistant magnetic pump refers to fluoroplastic magnetic pump and stainless steel magnetic pump based on fluoroplastics and stainless steel.

Fluoroplastic magnetic pump flow components are mainly F46, the remaining materials are silicon carbide spindle, pump body static ring, impeller back ring, sliding bearing; and sealing of fluorine rubber sealing ring.

F46 can withstand corrosion in all media, but silicon carbide material has a tolerance range. Due to economic factors, the standard silicon carbide produced by fluoroplastic magnetic pump is reaction-sintered silicon carbide, the purity of which is generally between 93% and 95%. The remaining 5% is mainly silica crystal. Silicon carbide is also very stable at room temperature, but silicon dioxide will react with many media at room temperature, such as caustic soda, hydrofluoric acid, phosphate and so on. The chemical reaction equation is as follows:

Reaction of caustic soda with silica: Sio2 + 2NaOH = Na2SiO3 + H2O

Reaction of hydrofluoric acid with silica: 6HF + Sio2 + H2SiF6 + 2H2O

The above reaction will destroy the main structure of silicon carbide, improve the surface roughness of silicon carbide, turn into a grinding state, and accelerate the wear rate of the grinding parts. Therefore, in the selection of materials must study the corrosive transport medium, otherwise it will shorten the corrosion resistance magnetic pump service life.

When conveying nitric acid, organic solvents and other media, fluorine rubber sealing ring should not be selected, because fluorine rubber seal ring in nitric acid and organic solvents will expand and lose elasticity, which will affect the sealing performance.

Stainless steel magnetic pump is mainly based on austenitic stainless steel. The corrosion resistance of austenitic stainless steel magnetic pump is poor in acid medium, but it is inert in alkaline corrosion medium. So in the solution containing alkaline medium generally choose stainless steel corrosion resistant magnetic pump.

In addition to the overcurrent component of austenitic stainless steel, the remaining materials immersed in the medium include: sic, tungsten carbide, austenitic stainless steel after ion nitriding, and perfluorinated gaskets.

The reaction of Silicon Carbide in Alkali solution as described above, tungsten carbide, ion-nitrided stainless steel and so on, all show extremely inert in alkali solution. Therefore, when conveying caustic soda and other media, the general choice of tungsten carbide grinding parts.