As the most common mechanical equipment, the pump has a very wide range of applications. It can be used in various industries, various environments, and various fluid media. We can choose different types and materials of pumps according to the application environment and fluid medium of the pump. As a pump foundry, we have produced pumps of all types and materials. This blog will introduce how to choose pump material for different fluid media.
Selection of pump material in sulfuric acid medium
Sulfuric acid is a very important industrial raw material. It’s very versatile. But it is also one of the strong corrosive acids. The corrosion strength of sulfuric acid is related to its temperature and different concentrations. For specific material selection, we can refer to the following:
1- Cast iron and carbon steel have good corrosion resistance and can be used for concentrated sulfuric acid with a concentration of more than 80% and a temperature of less than 80 °C. But cast iron and carbon steel are not suitable for pump valve materials. and sulfuric acid requires high-speed flow.
2-zirconium alloy stainless steel and high silicon cast iron pump valve can be used to transport sulfuric acid.
3- The pump lined with fluorine can also be used for the delivery of sulfuric acid medium. Fluoroplastics are inexpensive and have good acid resistance.
Our common stainless steel such as 304, 316 and so on. They are not very resistant to strong acids. So, it is not recommended to choose stainless steel.
Selection of pump material in hydrochloric acid medium
Our common metal materials are almost not resistant to hydrochloric acid corrosion. Includes various stainless steels. Of course, if the concentration of delivered hydrochloric acid is less than 30%, and the temperature of hydrochloric acid is less than 50 °C, molybdenum-containing ferrosilicon can be selected as the material.
Although many metals cannot be used in hydrochloric acid environments. But most non-metallic materials can be used in hydrochloric acid environments. They have good corrosion resistance to hydrochloric acid. We can choose to have the inside of the pump lined with rubber or plastic.
Selection of pump material in alkaline medium
For the pump materials chosen for transporting alkaline media, the following recommendations can be found.
1-Steel can be used in sodium hydroxide solution. but the temperature of sodium hydroxide solution should be below 80℃. The concentration should be below 30%.
2- It is not recommended to use ordinary stainless steel pumps to transport alkaline media. Compared with cast iron, ordinary stainless steel has no obvious advantage in corrosion resistance to alkaline solutions.3-Pumps made of titanium, titanium alloy or high alloy stainless steel can be used for lye in high-temperature conditions.4- If cost is to be considered. Pumps made of ordinary steel can also be used for alkaline solutions with a temperature of 100°C and a concentration of less than 75%. Although the corrosion is increased and the life is reduced, the price is cheap.
Selection of pump material in nitric acid medium
For the selection of pump materials for conveying nitric acid media, please refer to the following suggestions:1-Stainless steel pump can be used to transport nitric acid medium. Stainless steel is the most widely used nitric acid-resistant material. It has good corrosion resistance to nitric acid at room temperature.
2- The pump made of titanium and titanium alloy can be used for the delivery of high-temperature nitric acid.
3- Compared with ordinary stainless steel (304 stainless steel, 321 stainless steel), molybdenum-containing stainless steel (316, 316Lu stainless steel) is not very resistant to nitric acid corrosion.
Selection of pump material in acetic acid medium
As one of the most corrosive substances in organic acids. Acetic acid at all concentrations and temperatures is severely corrosive to ordinary steel. For the pump material for conveying acetic acid medium, please refer to the following suggestions:1-Stainless steel pump can be used for the delivery of acetic acid. Stainless steel has good resistance to acetic acid.
2-316 stainless steel contains molybdenum. The 316 stainless steel pump can also be used for high-temperature acetic acid and dilute acetic acid steam.
3- The pump made of high alloy stainless steel and fluoroplastic can be used for high temperature and high concentration and acetic acid containing other corrosive media.
Selection of pump material in ammonia medium
Our common metals and non-metals have good ammonia corrosion resistance. They are slightly corroded in liquid ammonia and ammonium hydroxide. Besides to copper and copper alloys, almost all materials can be used for the delivery of ammonia media.
Selection of pump material in saline medium
For the pump material for conveying acetic acid medium, please refer to the following suggestions:
1- In saltwater environments, 316 stainless steel pumps are usually used. Other stainless steels may cause localized corrosion due to chloride ions
2- In sodium chloride solution and seawater, salt water. Pumps made of ordinary steel need paint protection. Material selection for alcohols, ketones, esters, ethers, and other media
Our common alcohols, esters, ketones, and ethers include
- Alcohols: methanol, ethanol, ethylene glycol, propanol, etc.;
- Esters: methyl ester, ethyl ester, etc.;
- Ketones: acetone, butanone, etc.;
- Ethers: methyl ether, ether, butyl ether, etc.
The above medium is basically non-corrosive. And the material of the pump can be a common material. But there is one more thing to note. When selecting the material of the pump, it is also necessary to make a reasonable choice according to the properties of the medium and related requirements. For example, ketones, esters, and ethers are soluble in various rubbers. So we need to pay attention to the choice of materials when choosing the sealing material of the water pump.
Contact us if you don’t know how to choose pump material for different fluid media. We can cast pump casings, impellers and other casting parts for customers with customized materials.