Hydrofluoric acid is an aqueous solution of hydrogen fluoride gas, a clear, colorless, corrosive liquid that emits smoke. It has a strong irritating odor and is highly volatile. When exposed to air, it emits white smoke. Although it is non flammable, it can react with most metals to generate hydrogen gas and cause explosions. Hydrofluoric acid is a highly hazardous poison that can easily cause skin ulcers when touched. Inhaling its vapor can be fatal. So what special requirements do we need to pay attention to when selecting chemical pumps suitable for hydrofluoric acid media?

Firstly, although hydrofluoric acid is theoretically a low solubility weak acid, it has corrosive properties. Therefore, when choosing a chemical pump, corrosion-resistant fluoroplastic chemical pumps are generally suitable, such as fluoroplastic magnetic pumps and fluoroplastic centrifugal pumps. The impeller and pump cover in fluoroplastic pumps are all made of metal inserts wrapped in fluoroplastic and sintered as a whole. The main part of the pump body is made of HT200 lined with F46.

For special corrosive media such as hydrofluoric acid, the mechanical seal dynamic and static rings of fluoroplastic centrifugal pumps, as well as the main shaft, shaft sleeve, dynamic and static rings of fluoroplastic magnetic pumps, must be made of pressureless sintered silicon carbide material. The pump seal must be replaced with an outer PTFE material.
The reason for this is due to the relatively strong binding ability between hydrogen and fluorine atoms, which makes hydrofluoric acid unable to ionize in water and has corrosive properties. It can strongly corrode metals, glasses, and silicon containing objects. Therefore, ordinary Sic silicon carbide contains impurities such as free silicon and silicon dioxide, which are easily corroded by hydrofluoric acid. After corrosion, the smoothness of the polished surface will be destroyed, thereby affecting the service life of the pump.