Chemical industry play a very important role in the national economy. And chemical process pumps as a key supporting equipment has been paid more and more attention. How to select the chemical pump correctly is the most important concern of users. Due to the complexity of chemical media, the correct choice of users becomes the key.
Chemical process pump common transport liquid:Acid, Alkali, Salt, etc.
Acetic acid: it is one of the most corrosive substances in organic acids. Ordinary iron and steel will be corroded seriously in acetic acid. High-alloy stainless steel chemical pump or fluoroplastic pump can be used for high concentration acetic acid.
Hydrochloric acid: Most of metals are not resistant to hydrochloric acid (including various stainless steel materials). So lined rubber pumps and plastic pumps (such as polypropylene, fluoroplastics, etc.) are the best choice for the delivery of hydrochloric acid. Use product: IHF lined fluorine pump, strong corrosion resistance centrifugal pump, fluoroplastic magnetic pump.
Nitric acid:Generally metal is rapidly corroded and destroyed in nitric acid. Stainless steel material is the most widely used nitric acid. It’s have a good corrosion resistance at normal temperature.
Applicable products:Chemical pump, corrosion resistance centrifugal pump, IH Chemical pump, Magnetic pump.
Sulfuric acid:A very wide range of important industrial raw materials. Sulfuric acid with different concentrations and temperatures has a great difference in corrosion of materials. Therefore, chemical pumps that transport sulfuric acid are usually made of high-silicon cast iron (difficult to cast and process) high-alloy stainless steel (20 alloy).It is usually more economical to use a fluorine-lined pump (PTFE).
Applicable products:IHF lined fluorine pump, strong corrosion resistant centrifugal pump, fluoroplastic magnetic pump
Chemical products should pay attention to the choice of sealing during transportation. Leakage of toxic and explosive products can easily lead to major disasters.
No leakage is the goal pursued by chemical equipment. It is this requirement that has led to the expansion of the application of magnetic pumps and canned pumps. There is still a long way to go before there is no leakage. Such as the life of the magnetic pump isolation sleeve and the canned pump, the pitting problems of materials, reliability issues with static seals, etc.
Static sealing: Chemical pumps are usually based on gaskets and sealing ring. The gasket is mainly flat gasket. (Our company has repeated experiments, adding two semi-circles at both ends of the sealing surface of the flat gasket, and the sealing performance is improved.) The sealing ring is widely used in O-rings.
Dynamic sealing: mainly for mechanical seal application, mechanical seal is divided into single end and double end, packing seal, balance type and non-equilibrium type. The double-face machine seal is mainly used for high temperature, easy crystallization, viscosity, and toxic medium; packing seal is suitable for medium containing solid small particles; balance type is suitable for sealing of high pressure medium.
The material selection of chemical pump static sealing is generally fluororubber. In special cases, polytetrafluoroethylene (such as organic solvent) is used. The mechanical seal static ring and dynamic ring material configuration are more important. It is not the best for hard alloys to hard alloys.There is no hardness difference in two hard alloys, also price high than normal. So we choose should be thinks about the characteristics of the medium.