Technical parameters of chemical pump

1. As one of the strong corrosive media, sulfuric acid is an important industrial raw material with a wide range of uses. The corrosion of materials varies greatly with different concentrations and temperatures of sulfuric acid. For concentrated sulfuric acid with concentrations above 80% and temperatures below 80 ℃, carbon steel and cast iron have good corrosion resistance, but they are not suitable for high-speed flowing sulfuric acid and are not suitable as materials for pumps and valves; Ordinary stainless steels such as 304 (0Cr18Ni9) and 316 (0Cr18Ni12Mo2Ti) also have limited applications in sulfuric acid media. Therefore, pumps and valves for transporting sulfuric acid are usually made of high silicon cast iron (difficult to cast and process) and high alloy stainless steel (No. 20 alloy). Fluoroplastics have good sulfuric acid resistance, and using a fluorine lined pump (F46) is a more economical choice.
2. Most metal materials, including various stainless steel materials, are not resistant to hydrochloric acid corrosion. Molybdenum containing high silicon iron can only be used for hydrochloric acid below 50 ℃ and 30%. Contrary to metal materials, the vast majority of non-metallic materials have good corrosion resistance to hydrochloric acid, so lined rubber pumps and plastic pumps (such as polypropylene, fluoroplastics, etc.) are the best choices for transporting hydrochloric acid.
Most metals in nitric acid are rapidly corroded and destroyed in nitric acid. Stainless steel is the most widely used nitric acid resistant material, which has good corrosion resistance to all concentrations of nitric acid at room temperature. It is worth mentioning that stainless steel containing molybdenum (such as 316, 316L) not only does not have better corrosion resistance to nitric acid than ordinary stainless steel (such as 304, 321), but sometimes even worse. For high-temperature nitric acid, titanium and titanium alloy materials are usually used.
4. Acetic acid is one of the most corrosive substances among organic acids. Ordinary steel will suffer severe corrosion in all concentrations and temperatures of acetic acid. Stainless steel is an excellent acetic acid resistant material, and 316 stainless steel containing molybdenum can also be suitable for high temperatures and dilute acetic acid vapors. For demanding requirements such as high temperature and high concentration acetic acid or other corrosive media, high alloy stainless steel pumps or fluoroplastic pumps can be selected.
5.Alkaline (sodium hydroxide) steel is widely used in sodium hydroxide solutions below 80 ℃ and within 30% concentration. Many factories still use ordinary steel at temperatures below 100 ℃ and 75%, although corrosion increases, it has good economic efficiency. Compared with cast iron, ordinary stainless steel does not have significant advantages in corrosion resistance to alkaline solution. As long as a small amount of iron is allowed to be added to the medium, stainless steel is not recommended. For high-temperature alkaline solutions, titanium and titanium alloys or high alloy stainless steel are often used.