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  • Address:Yongfeng town industrial park, tianchang city, Chuzhou city, Anhui province
How to choose the material of high performance corrosion res

The corrosion resistant chemical pump is a special type of chemical pump classified according to its purpose. Corrosion resistant chemical pumps are widely used in the chemical pump industry, such as liquid or solid chemical materials used to transport strong acid, strong alkali and high temperature. Because of the special object of corrosion resistant chemical pump, the selection and manufacture of the pump are very complex, and the price is not low. Most of the pump is made of metal materials, metal corrosion in different, such as carbon steel in dilute sulfuric acid corrosion faster, but in concentrated sulfuric acid is quite stable, some corrosion of stainless steel chemical pump of alkali or steam of petroleum products is relatively stable, but the sulfuric acid and strong acid is relatively poor. So how to choose the high performance corrosion resistant chemical pump has become a basic skill in the industry. Below is how to choose the material of the chemical pump on the different kinds of medium.

As one of the strong corrosion medium, 1. sulfuric acid is an important industrial raw material which is very widely used. Corrosion difference of different concentration and temperature of sulfuric acid material is large, the sulfuric acid concentration is above 80%, the temperature less than 80 DEG C, carbon steel and cast iron has good corrosion resistance, but it is not suitable for high-speed flow of sulfuric acid, not suitable for pump materials; ordinary stainless steel such as 304 (0Cr18Ni9), 316 (0Cr18Ni12Mo2Ti) the sulfuric acid also of limited use. Therefore, the pump of sulphuric acid is usually made of high silicon cast iron (difficult casting and processing) and high alloy stainless steel (No. 20 alloy). Fluoroplastics have good sulphuric acid resistance, and the use of fluorine lining pump (F46) is a more economical choice. Applicable products are: IHF fluorine pump, PF strong corrosion resistant centrifugal pump, CQB-F fluoroplastic magnetic pump, and so on.

2. nitric acid most of the general metal corrosion in nitric acid was rapidly destroyed, stainless steel is the most widely used nitric acid resistant materials have good corrosion resistance, all concentrations of nitric acid at room temperature, it is worth mentioning that the stainless steel containing molybdenum (316, 316L) of nitric acid corrosion resistance is not only no better than ordinary stainless steel (as of 304, 321), sometimes even better. For high temperature nitric acid, titanium and titanium alloy are usually used. The applicable products of the company are: IH chemical pump, CQB magnetic pump and so on. The material is 304.

3. acetic acid is one of the most corrosive substances in organic acids. Ordinary steel will seriously corrode in acetic acid at all concentrations and temperatures. Stainless steel is excellent acetic acid resistant material, and molybdenum containing 316 stainless steel can also be applied to high temperature and dilute acetic acid steam. High alloy stainless steel or fluoroplastic pump can be used for high temperature and high concentration acetic acid or other harsh requirements for corrosion medium.

4. hydrochloric acid in the majority of metal materials is not resistant to hydrochloric acid corrosion (including all kinds of stainless steel), and molybdenum high ferrosilicon can also be used only for hydrochloric acid below 50 C and 30%. Contrary to metal materials, most non-metallic materials have good corrosion resistance to hydrochloric acid, so lining rubber pumps and plastic pumps, such as polypropylene and fluoroplastics, is the best choice for transporting hydrochloric acid. Applicable products are: IHF liner fluorine pump, PF strong corrosion resistant centrifugal pump, CQ polypropylene magnetic pump (or fluoroplastic magnetic pump), etc.

5. salt water (sea water) ordinary steel in Sodium Chloride Solution and sea water, salt water corrosion rate is not high, are generally required to use paint protection; all kinds of stainless steel has a very low corrosion rate, but may be due to localized corrosion caused by chloride ions, typically 316 stainless steel is better. All kinds of chemical pumps in the company have 316 materials.

6. the corrosion of most metals and nonmetals in the liquid ammonia and ammonia (hydrogen oxide ammonia) is very slight, only copper and copper alloys are not suitable for use. Most of the company's products are suitable for the transportation of ammonia and ammonia water.

7. alcohols, ketones, esters, ethers common alcohols media are methanol, ethanol, ethylene glycol, alcohol, ketones medium with acetone and butanone, a variety of media methyl esters, ethyl ester, ether medium with ether, butyl ether, etc., they are basically no corrosive materials can be used for, also we should make a reasonable choice according to the relevant requirements of the medium properties and specific use. It is also worth noting that ketones, esters, and ethers are soluble in many kinds of rubber, and avoid errors when choosing sealing materials.

The 8. alkali (sodium hydroxide) steel is widely used in sodium hydroxide solution below 80 and 30% concentration. Many factories still use ordinary steel at 100 and 75%, although the corrosion is increased, but the economy is good. The corrosion resistance of common stainless steel to alkaline solution has no obvious advantages compared with cast iron, as long as a small amount of iron is admissible in the medium, and stainless steel is not recommended. For high temperature alkaline solution, titanium and titanium alloy or high alloy stainless steel are mostly used. The general cast iron pump of the company can be used for low concentration alkaline solution at normal temperature. All kinds of stainless steel pumps or fluoroplastic pumps can be used when special requirements are required.


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