Yingkou chemical acid pump co., LTD. How to teach you acid pump selection
Date:2019-03-15 Author: Click:
The selection of acid-resistant pumps has long been one of the biggest headaches for chemical industry practitioners.According to relevant statistics, about 60% of the destruction of chemical equipment is caused by corrosion, so in the chemical pump selection should first pay attention to the scientific selection of materials.There is a kind of misunderstanding normally, think stainless steel is "all-purpose material", no matter what medium and environmental condition hold out stainless steel, this is very dangerous.The following for some common chemical media to talk about the main points of material selection:
1. As one of the strongly corrosive media, sulfuric acid is an important industrial raw material with a wide range of USES.Corrosion of different concentration and temperature of sulfuric acid on the material difference is bigger, the concentration is above 80%, the temperature is less than 80 ℃ concentrated sulfuric acid, carbon steel and cast iron has good corrosion resistance, but it is not suitable for high-speed flow of sulfuric acid, is not used as a pump valve materials;Common stainless steel such as 304 (0Cr18Ni9), 316 (0Cr18Ni12Mo2Ti) for sulfuric acid medium is also limited use.Therefore, the delivery of sulfuric acid pump valve is usually used high silicon cast iron (casting and processing difficult), high alloy stainless steel (20 alloy) manufacturing, but its processing difficult and expensive, so it is not expected.Fluoroplastic alloy centrifugal pump has a good resistance to sulfuric acid performance, it is a patent material of Shanghai institute of organic chemistry, Chinese academy of sciences, by the Chinese academy of sciences experiment proved that there is no chemical medium and its reaction, so using fluoroplastic (F46) is a more economical choice.Applicable products: IHF fluorine pump, FSB strong corrosion resistant centrifugal pump, CQB fluoroplastic magnetic pump, etc.
2. The vast majority don't hydrochloric acid corrosion resistant metal materials hydrochloride (including all kinds of stainless steel materials), also can only be used for high silicon molybdenum 50 ℃ and below 30% hydrochloric acid.In contrast to metallic materials, most non-metallic materials have good corrosion resistance to hydrochloric acid, so lining rubber pump and plastic pump (such as engineering plastics, fluoroplastic, etc.) is the best choice for transporting hydrochloric acid.Applicable products are: CQB fluoroplastic leakage-free acid-proof pump, CQF engineering plastic magnetic pump (or fluoroplastic magnetic pump), etc.
3. The most general metal nitrate was rapidly in nitric acid corrosion damage, stainless steel is the most widely used of nitric acid resistant material, all on room temperature the concentration of nitric acid have good corrosion resistance, it is important to note that the molybdenum stainless steel (e.g., 316, 316 l) of nitric acid corrosion resistance not only no better than ordinary stainless steel (e.g., 304, 321), sometimes even less.For high-temperature nitric acid, fluoroplastic alloys are usually used.The company's applicable products are: IHF fluoroplastic alloy magnetic pump, FSB fluoroplastic alloy centrifugal pump, etc.
4 acetic acid it is one of the most corrosive substances in organic acid, ordinary steel in all concentration and temperature of acetic acid will seriously corrosion, stainless steel is an excellent anti-acetic acid material, molybdenum-containing 316 stainless steel is also suitable for high temperature and dilute acetic acid steam.For high temperature high concentration acetic acid or contain other corrosive medium such as demanding, can choose high alloy stainless steel or fluoroplastic pump.Production of CQB magnetic pump, FZB fluoroplastic self - priming pump.
5. Alkali (sodium hydroxide) is generally not very corrosive, but generally the alkali solution will produce crystallization, so it is optional to configure IHF type fluorine alloy alkali pump with mechanical seal made of silicified graphite 169 material
6. Ammonia (ammonia hydroxide) the corrosion of most metals and non-metals in liquid ammonia and ammonia water (ammonia hydroxide) is very minor, and only copper and copper alloys are not suitable for use.Most of the company's products are suitable for the transmission of ammonia and ammonia water.The production of CQF engineering plastic magnetic pump, FSB fluorine alloy centrifugal pump is better
7. The corrosion rate of ordinary steel in salt water (sea water) is not too high in sodium chloride solution, sea water and salt water, so coating protection is generally required;All kinds of stainless steel also have very low uniform corrosion rate, but may cause local corrosion due to chloride ions, usually 316 stainless steel is better.All kinds of chemical pumps are equipped with 316 materials, such as IH chemical centrifugal pump.
8. Alcohols, esters, ketones, ethers, common alcohol medium such as methanol, ethanol, ethylene glycol, propylene glycol, ketone medium such as acetone, butanone, there are all kinds of methyl esters medium, ethyl ester, ethers media such as methyl ether, ethyl ether, butyl ether, their basic is not strong corrosive, so all can choose ordinary stainless steel, concrete selection should also according to the requirements of the dielectric properties and related make reasonable choice.It is also worth noting that ketone, ester, ether on a variety of rubber solubility, to avoid errors in the selection of sealing materials.It is recommended to choose the inorganic sealed fluoroplastic magnetic pump
Acid-proof pump selection
Horizontal acid - resistant pump is the most widely used pump for conveying acid medium.Secondly, the hydraulic pump is also used more pumps, some manufacturers due to the problem of sealing horizontal pump, habitual use of hydraulic pump.
Acid pump preferredYingkou chemical acid pump co. LTD