Tips for selecting acid resistant pumps
How should acid resistant pumps be selected? Here are some tips. Firstly, it depends on what type of acid you are conveying. Below are several common selection methods for acid resistant pumps:
1. Hydrochloric acid pump
The highest concentration of commonly used hydrochloric acid is 38%, so pumps for hydrochloric acid generally only need to be made of plastic as the flow passage component. However, when considering service life and cost-effectiveness, FSB fluorine alloy centrifugal pumps or CQB-F magnetic pumps can be selected. The prices and performance of these two pumps are satisfactory.
2. Sulfuric acid pump
Sulfuric acid pumps are divided into dilute sulfuric acid pumps and concentrated sulfuric acid pumps. The former has a wide range of options. Dilute sulfuric acid pumps can be selected from engineering plastic pumps, ceramic pumps, F46 pumps, or F26 pumps. The latter (concentrated sulfuric acid pumps) can only choose fluoroplastic (F46) pumps because concentrated sulfuric acid can corrode ordinary engineering plastics, while fluoroplastics will not be corroded. It should also be noted that the density of concentrated sulfuric acid is relatively high. When selecting a pump, attention should be paid to increasing the motor power. A simple algorithm is "shaft power" * 1.84, which is the shaft power when transporting concentrated sulfuric acid.
3. Hydrofluoric acid
The corrosiveness of hydrofluoric acid is very strong. It is recommended to choose a fluoroplastic magnetic pump (and the ceramic parts of this series of pumps must be replaced with hydrofluoric acid resistant materials)
4. Nitric acid
It is also recommended to use fluoroplastic magnetic pumps for nitric acid delivery pumps, and the rubber sealing rings should be replaced with PTFE materials.
5. Acetic acid
It is one of the most corrosive substances in organic acids. Ordinary steel will severely corrode in all concentrations and temperatures of acetic acid. Stainless steel is an excellent acetic acid resistant material, and 316 stainless steel containing molybdenum can also be suitable for high temperatures and dilute acetic acid vapors. For demanding requirements such as high temperature and high concentration acetic acid or containing other corrosive media, high alloy stainless steel or fluoroplastic magnetic pumps can be selected. For example, CQB magnetic pump and CQ316L stainless steel magnetic pump
6. Salt water (seawater)
Ordinary steel has a low corrosion rate in sodium chloride solution, seawater, and salt water, and generally requires coating protection; Various types of stainless steel also have a low uniform corrosion rate, but may cause localized corrosion due to chloride ions. Usually, 316 stainless steel is preferred, but its price is relatively high. It is recommended to choose fluoroplastic centrifugal pumps, such as IHF chemical centrifugal pumps.
7. Sealing
Sealing form: Magnetic pumps are in static sealing form, so sealing performance can be ignored. Centrifugal pumps generally use external corrugated pipe mechanical seals, which have good corrosion and wear resistance. If the medium being transported contains particles, hard to hard mechanical seals can be used.
1. Hydrochloric acid pump
The highest concentration of commonly used hydrochloric acid is 38%, so pumps for hydrochloric acid generally only need to be made of plastic as the flow passage component. However, when considering service life and cost-effectiveness, FSB fluorine alloy centrifugal pumps or CQB-F magnetic pumps can be selected. The prices and performance of these two pumps are satisfactory.
2. Sulfuric acid pump
Sulfuric acid pumps are divided into dilute sulfuric acid pumps and concentrated sulfuric acid pumps. The former has a wide range of options. Dilute sulfuric acid pumps can be selected from engineering plastic pumps, ceramic pumps, F46 pumps, or F26 pumps. The latter (concentrated sulfuric acid pumps) can only choose fluoroplastic (F46) pumps because concentrated sulfuric acid can corrode ordinary engineering plastics, while fluoroplastics will not be corroded. It should also be noted that the density of concentrated sulfuric acid is relatively high. When selecting a pump, attention should be paid to increasing the motor power. A simple algorithm is "shaft power" * 1.84, which is the shaft power when transporting concentrated sulfuric acid.
3. Hydrofluoric acid
The corrosiveness of hydrofluoric acid is very strong. It is recommended to choose a fluoroplastic magnetic pump (and the ceramic parts of this series of pumps must be replaced with hydrofluoric acid resistant materials)
4. Nitric acid
It is also recommended to use fluoroplastic magnetic pumps for nitric acid delivery pumps, and the rubber sealing rings should be replaced with PTFE materials.
5. Acetic acid
It is one of the most corrosive substances in organic acids. Ordinary steel will severely corrode in all concentrations and temperatures of acetic acid. Stainless steel is an excellent acetic acid resistant material, and 316 stainless steel containing molybdenum can also be suitable for high temperatures and dilute acetic acid vapors. For demanding requirements such as high temperature and high concentration acetic acid or containing other corrosive media, high alloy stainless steel or fluoroplastic magnetic pumps can be selected. For example, CQB magnetic pump and CQ316L stainless steel magnetic pump
6. Salt water (seawater)
Ordinary steel has a low corrosion rate in sodium chloride solution, seawater, and salt water, and generally requires coating protection; Various types of stainless steel also have a low uniform corrosion rate, but may cause localized corrosion due to chloride ions. Usually, 316 stainless steel is preferred, but its price is relatively high. It is recommended to choose fluoroplastic centrifugal pumps, such as IHF chemical centrifugal pumps.
7. Sealing
Sealing form: Magnetic pumps are in static sealing form, so sealing performance can be ignored. Centrifugal pumps generally use external corrugated pipe mechanical seals, which have good corrosion and wear resistance. If the medium being transported contains particles, hard to hard mechanical seals can be used.
