Four problems must be paid attention to in industrial pump selection
The corrosion problem of industrial pump
Below for some commonly used chemical medium to talk about the selection of points:
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. Sulfuric acid concentration and temperature on Corrosion of materials in large difference, more than 80% concentration, temperature less than 80 DEG C concentrated sulfuric acid, carbon steel and cast iron has good corrosion resistance, but it is not suitable for high-speed flow of sulfuric acid, does not apply as pump material; ordinary stainless steel such as 304 (0Cr18Ni9), 316 (0Cr18Ni12Mo2Ti) of sulfuric acid is of limited use. Delivery of sulfuric acid pump valve is usually made of high silicon cast iron (casting and machining difficult), high alloy stainless steel (alloy 20) manufacturing. Fluorine plastic has good resistance to sulfuric acid, using fluorine pump (F46) is a more economical choice. The company applies to products: IHF fluorine pump, PF (FS) strong corrosion resistant centrifugal pump, CQB-F 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, lined rubber pump and plastic pumps (such as polypropylene, fluorine plastic, etc.) is the best choice for hydrochloric acid transport. The company applies to products: IHF fluorine pump, PF (FS) strong corrosion resistant centrifugal pump, CQ polypropylene magnetic pump (or fluorine plastic magnetic pump), etc..
3 most of the general metal nitrate nitric acid was rapid corrosion, stainless steel is the most widely used nitric acid resistant materials, has good corrosion resistance to temperature all concentrations of nitric acid, worth mentioning is the stainless steel containing molybdenum (316, 316L) on the nitric acid corrosion resistance is not better than ordinary stainless steel (304, 321),. The high temperature nitric acid, usually titanium and titanium alloy materials. Company's products are: DFL (W) H chemical pump, DFL (W) PH shielding chemical pump, DFCZ flow pump, DFLZP self-priming pump, IH chemical pump, CQB magnetic pump, etc., 304.
4 acetic acid is one of the most corrosive substances in organic acids
Severe corrosion, stainless steel is an excellent acid resistant material, containing molybdenum 316 stainless steel can also be applied to high temperature and dilute acetic acid vapor. High temperature and high concentration of acetic acid or other corrosive media and other harsh requirements, can choose high alloy stainless steel or fluorine plastic pump.
5 alkali (sodium hydroxide) iron and steel widely used in the temperature of 80 degrees Celsius, the concentration of sodium hydroxide solution, there are many factories in the temperature of 100 DEG C, less than 75% of the ordinary steel, corrosion, but the economy is good. The alkali corrosion resistance of ordinary stainless steel and cast iron had no obvious advantages, medium to allow incorporation of a small amount of iron stainless steel is not recommended. The use of high temperature alkali titanium and titanium alloy of high alloy stainless steel. The company generally cast iron pumps can be used for low concentration of alkali at room temperature, special requirements can be used all kinds of stainless steel pumps or fluorine plastic pump.
6 ammonia (ammonium hydroxide) most of the metal and nonmetal liquid ammonia and ammonia (ammonium hydroxide) in the corrosion is very slight, copper and copper alloy should not be used. Most of the products are suitable for ammonia and ammonia.
7 salt water (sea water) ordinary steel 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. Various types of chemical pumps have 316 material configuration.
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 are basically no corrosive materials can be used to apply. The specific use should also be medium properties and related requirements to make reasonable choices. In addition, the attention is paid to ketones, esters, ethers of a variety of rubber solubility, select the sealing material to avoid mistakes.