All along, corrosion is one of the most troublesome hazards of chemical equipment, a slight carelessness, ranging from damage to equipment, heavy cause accidents and even lead to disaster. According to the statistics, about 60% of the destruction of chemical equipment is caused by corrosion. Therefore, the selection of chemical pumps should first pay attention to the scientific material selection. There is often a misunderstanding that stainless steel is a "universal material," no matter what the media and environmental conditions are held stainless steel pump, which is very dangerous. The following for some common chemical media to talk about the selection of the main points: This article Keywords: pump Pressure Washer Wand,Power Washer Wand,Pressure Washer Extension Wand,High Pressure Washer Extension Wand Ningbo Senmiao Trading Co., Ltd. , https://www.nbsenmiao.com
1. Sulfuric acid as a strong corrosive medium, sulfuric acid is an important use of a wide range of industrial raw materials. Different concentrations and temperatures of sulfuric acid on the corrosion of materials vary greatly, for the concentration of more than 80%, the temperature is less than 80 ℃ of concentrated sulfuric acid, 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 valve material; common stainless steel such as 304 (0Cr18Ni9), 316 (0Cr18Ni12Mo2Ti) sulfuric acid medium is also limited use. Therefore, the delivery of sulfuric acid pump valve usually adopts high silicon cast iron (casting and processing difficult), high alloy stainless steel (20 alloy) manufacturing. Fluoroplastic has good resistance to sulfuric acid, the use of fluorine pump (F46) is a more economical choice. Company products are: IHF fluoride plastic chemical pump, PF (FS) strong corrosion-resistant centrifugal pumps, CQB-F Fluorine plastic magnetic pump.
2. Hydrochloric acid solution Most of the metal materials are not resistant to hydrochloric acid corrosion (including a variety of stainless steel), molybdenum high ferrosilicon can only be used for 50 ℃, 30% hydrochloric acid. In contrast to metallic 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, fluoroplastic, etc.) is the best choice for the delivery of hydrochloric acid. Company products are: IHF fluoride plastic chemical pump, PF (FS) strong corrosion-resistant centrifugal pumps, CQ polypropylene magnetic pump (or fluorine plastic magnetic pump).
3. Nitric acid Most metals are mostly corrosive in nitric acid corrosion damage, stainless steel is the most widely used nitric acid-resistant materials, all concentrations of nitric acid at room temperature have good corrosion resistance, it is worth mentioning that the molybdenum-containing stainless steel (such as 316,316 L) corrosion resistance to nitric acid is not only not superior to ordinary stainless steel (such as 304,321), and sometimes even worse. For high temperature nitric acid, usually titanium and titanium alloy materials. The company applies products: DFL (W) H chemical pump, DFL (W) PH shielding chemical pump, DFCZ process pump, DFLZP self-absorption chemical pump, IH chemical pump, CQB magnetic pump,
4. Acetic acid It is one of the most corrosive substances in organic acids. Ordinary steel will be seriously corroded in all concentrations and temperatures of acetic acid. Stainless steel is an excellent acetic acid-resistant material. Molybdenum-containing 316 stainless steel is also suitable for high temperature and Dilute acetic acid steam. For high temperature and high concentration of acetic acid or other corrosive media and other harsh requirements, the choice of high alloy stainless steel pump or fluorine plastic pump.
5. Alkali (sodium hydroxide) steel is widely used in sodium hydroxide solution below 80 ℃, 30% concentration, there are many factories at 100 ℃, 75% below the ordinary steel is still used, although the corrosion increases, but the economy is good . Ordinary stainless steel lye corrosion resistance and cast iron compared with no obvious advantages, as long as the medium allows a small amount of iron content is not recommended for incorporation of stainless steel. For high temperature alkaline use of titanium and titanium alloy or high alloy stainless steel. The company generally cast iron pump can be used for low temperature lye concentration, special requirements can be used when all kinds of stainless steel pump or fluorine plastic pump.
6. Ammonia (ammonia hydroxide) Most metals and non-metals in liquid ammonia and ammonia (ammonia hydroxide) corrosion are minor, only copper and copper alloy should not be used. Most of the company's products for ammonia and ammonia transport.
7. Saline (seawater) Common steel corrosion rate in sodium chloride solution and seawater, salt water is not too high, the general shall be used paint protection; various types of stainless steel also have a low uniform corrosion rate, but may be due to chloride ions caused by the local Corrosion, usually 316 stainless steel is better. Various types of chemical companies have 316 material pump configuration.
8. alcohols, ketones, esters, ethers Common alcohol mediums are methanol, ethanol, ethylene glycol, propanol, ketones have acetone, butanone and so on, the ester medium has a variety of methyl esters, Ethyl ether, ethers medium ether, ether, butyl ether, they are basically non-corrosive, common materials are applicable, the specific selection should also be based on the media properties and related requirements to make a reasonable choice. It is also noteworthy that ketones, esters, ethers are soluble in a wide variety of rubbers and avoid mistakes when selecting sealing materials.
There are many other media can not be introduced in this one, in short, should not be arbitrarily and blindly selected materials, should consult more information or learn from mature experience.