All along, the type of acid pump is one of the most difficult problems in the chemical industry practitioners, a little careless, light damage to the equipment, causing serious accidents and even lead to disaster. According to statistics, about 60% of the destruction of chemical equipment is caused by corrosion, so the first choice in the selection of chemical pumps should pay attention to the scientific nature of the selection. Usually there is a misunderstanding that stainless steel is a universal material, no matter what the media and environmental conditions are holding out stainless steel, which is very dangerous. Below for some commonly used chemical media talk about the main points of selection:
1 sulfuric acid as one of the strong corrosive medium, sulfuric acid is the use of a very wide range of important industrial raw materials. 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 ordinary stainless steel valve materials; such as 304 (0Cr18Ni9), 316 (0Cr18Ni12Mo2Ti) the sulfuric acid also of limited use. Therefore, the delivery of sulfuric acid pump valve is usually high silicon cast iron (casting and machining difficult), high alloy stainless steel (alloy 20) manufacturing, but its processing is difficult and expensive, so people are not optimistic about. Fluorine plastic alloy with good resistance to sulfuric acid good performance, it is Chinese Academy of Sciences, Shanghai Institute of organic chemistry, the patent materials, my company in 1985 the introduction of patented technology, first with the development and production of corrosion-resistant chemical pumps, proved by the Chinese Academy of Sciences, yet which can react with the chemical medium, so using fluorine pump (F46) is a more economical choice. Fluorine source valve Co., Ltd. applicable products include: IHF fluorine pump, FSB strong corrosion resistant centrifugal pump, IMD fluorine plastic magnetic pump, etc..
The majority of 2 hydrochloric acid metal material are not resistant to hydrochloric acid corrosion (including stainless steel), molybdenum containing high silicon iron also can only be used for 50 DEG C, 30% hydrochloric acid. And metal materials, the vast majority of non-metallic materials have good corrosion resistance to hydrochloric acid, so lined with rubber and plastic pumps (such as engineering plastics, fluorine plastic, etc.) is the best choice of hydrochloric acid transport. Green ring pump company applies to products: CQB fluorine plastic leak free acid proof pump, CQF engineering plastic magnetic pump (or fluorine plastic magnetic pumps) etc..
3 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 the high temperature nitric acid, usually use fluorine plastic alloy material. The company applies to products: CQB fluorine plastic alloy magnetic pump, FSB fluorine alloy centrifugal pumps, etc..
4 acetic acid is one of the most corrosive substances in organic acids, ordinary steel will be severe corrosion in all the acetic acid concentration and temperature, acid resistant stainless steel is an excellent material, but also 316 stainless steel containing molybdenum for high temperature and dilute acetic acid vapor. For high temperature and high concentration of acetic acid or contain other corrosive media and other harsh requirements, can choose high alloy stainless steel or fluorine plastic pump. CQB magnetic pump, CQ stainless steel magnetic pump produced by fluorine source pump valve Co., ltd..
5 alkali (sodium hydroxide) general corrosion is not very strong, but generally will have a crystalline alkali solution, FSB fluorine alloy pump so you can use the configuration of the silicified graphite mechanical seal material 169
6 ammonia (ammonium hydroxide) most of the metal and metal in liquid ammonia and ammonia (ammonium hydroxide) in the corrosion is very slight, only copper and copper alloy should not be used. Most of the products are suitable for ammonia and ammonia. As a ring pump production company CQF engineering plastic magnetic pump, FSB fluorine alloy pump well
7 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. Green ring pump company has 316 types of chemical materials pump configuration, such as IH chemical centrifugal pump.
8 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, ethyl ether, butyl ether, etc., they basically do not corrosive, and therefore may use an ordinary stainless steel, also 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, ethers are soluble in a variety of rubber, the choice of sealing materials to avoid mistakes. Recommend the use of inorganic sealing fluorine plastic magnetic pump.