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How to Choose a Chemical Pump Correctly

2021-06-29

Choice of chemical pump:

1. Flow rate is one of the important performance data of pump selection, it is directly related to the production capacity and conveying capacity of the entire device. For example, in the process design of the design institute, the normal, minimum and maximum flow rates of the pump can be calculated. When selecting the pump, take the maximum flow rate as the basis and take into account the normal flow rate. When there is no maximum flow rate, usually 1.1 times the normal flow rate can be taken as the maximum flow rate.

2. Liquid properties, including the name of the liquid medium, physical properties, chemical properties and other properties. The physical properties include temperature c, density d, viscosity u, solid particle diameter and gas content in the medium, etc. This relates to the lift of the system, the effective gas Calculation of surplus and suitable pump type: chemical properties, mainly refer to the chemical corrosiveness and toxicity of the liquid medium, which is an important basis for the selection of pump materials and the selection of which type of shaft seal.

3. The piping layout conditions of the installation system refer to the liquid delivery height and the liquid delivery distance from the liquid delivery direction, the lowest liquid level on the suction side, the highest liquid level on the discharge side, etc. Some data and piping specifications and their lengths, materials, pipe fitting specifications, and quantities And so on, in order to carry out the combing head calculation and cavitation allowance check.

chemical pump

Materials that affect the choice of chemical pumps:

1. Most metals are quickly corroded and destroyed in nitric acid. Stainless steel is the most widely used nitric acid resistant material. It has good corrosion resistance to all concentrations of nitric acid at room temperature. It is worth mentioning that stainless steel containing molybdenum is resistant to nitric acid. The corrosion resistance is not better than ordinary stainless steel.

2. Acetic acid is one of the most corrosive substances in organic acids. Ordinary steel will be severely corroded in acetic acid at all concentrations and temperatures. Stainless steel is an excellent acetic acid resistant material. For demanding requirements such as high temperature and high concentration of acetic acid or other corrosive media, high alloy stainless steel or fluoroplastic pumps can be used.

3. The corrosion resistance of ordinary stainless steel to lye has no obvious advantages compared with cast iron. As long as a small amount of iron is allowed to be mixed in the medium, stainless steel is not recommended. For high-temperature lye, titanium and titanium alloy or high-alloy stainless steel are mostly used. The company's general cast iron pumps can be used for low-concentration lye at room temperature, and various stainless steel pumps or fluorine plastic pumps can be used for special requirements.

4. The corrosion of most metals and non-metals in liquid ammonia and ammonia water is very slight, only copper and copper alloys are not suitable for use. Most of the company's products are suitable for the transportation of ammonia and ammonia water.

5. Ordinary steel has a low corrosion rate in sodium chloride solution, seawater and salt water, and generally must be protected by paint; all kinds of stainless steel also have a very low uniform corrosion rate, but may cause localized corrosion due to chloride ions.