Selection of characteristics of high temperature and corrosion resistant pump delivery medium: According to different media, different high temperature and corrosion resistant pump models need to be selected.
1, sulfuric acid medium
As one of the strong corrosive media, sulfuric acid is an important industrial raw material with a wide range of uses. Different concentrations and temperatures of sulfuric acid have great differences in the corrosion of materials. For concentrated sulfuric acid with a concentration of more than 80% and a temperature of less than 80℃, carbon steel and cast iron have good corrosion resistance, but it is not suitable for high-speed flowing sulfuric acid. It is not suitable for use as a material for pump valves; ordinary stainless steels such as 304 (0Cr18Ni9) and 316 (0Cr18Ni12Mo2Ti) have limited use for sulfuric acid media. Therefore, pump 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), but their processing is difficult and expensive, so they are not favored by people. Fluoroplastic alloy has very good resistance to sulfuric acid. It is a patented material of Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences. Our company introduced the patented technology in 1985. It was the first to use it to develop and produce corrosion-resistant chemical pumps. The experiment proved by the Chinese Academy of Sciences. There is no chemical medium that can react with it, so it is a more economical choice to use a fluorine-lined pump (F46).
2, hydrochloric acid medium
Most metal materials are not resistant to hydrochloric acid corrosion (including various stainless steel materials), and high-silicon ferro-molybdenum can only be used in hydrochloric acid below 50°C and 30%. Contrary to metal materials, most non-metal materials have good corrosion resistance to hydrochloric acid, so rubber pumps and plastic pumps (such as engineering plastics, fluoroplastics, etc.) are the best choices for transporting hydrochloric acid.
3, nitric acid
Most metals are rapidly corroded in nitric acid. Stainless steel corrosion-resistant centrifugal pumps are the most widely used nitric acid-resistant centrifugal pumps. They have good corrosion resistance to all concentrations of nitric acid at room temperature. It is worth mentioning that stainless steel containing molybdenum The corrosion resistance of nitric acid (such as 316, 316L) is not better than that of ordinary stainless steel (such as 304, 321), and sometimes even worse. For high temperature nitric acid, fluoroplastic alloy materials are usually used.
4. Acetic acid
It is one of the most corrosive substances in organic acids. Ordinary steel will be severely corroded in acetic acid at all concentrations and temperatures. Stainless steel is an excellent acetic acid resistant material. 316 stainless steel containing molybdenum is also suitable for high temperature and dilute acetic acid vapor. . For harsh requirements such as high temperature and high concentration of acetic acid or other corrosive media, high alloy stainless steel magnetic pumps or fluoroplastic chemical pumps such as CQB stainless steel magnetic pump, CQ magnetic drive pump, stainless steel pipeline centrifugal pump, stainless steel chemical pump can be selected.
5. Alkali (sodium hydroxide) is generally not very corrosive, but general alkali solutions will produce crystallization.
6. Ammonia (Ammonia Hydroxide) Most metals and non-metals have slight corrosion in liquid ammonia and ammonia (Ammonia Hydroxide). Only copper and copper alloys are not suitable for use.
