How to choose a water pump in different media

How to choose a water pump in different media

1. Selection of material for sulfuric acid medium water pump

-sulfuric acid more than 80% and a temperature of less than 80 °,carbon steel and cast iron pumps have good corrosion resistance,

but they are not suitable for high-speed flowing sulfuric acid and are not suitable for use as pump valve materials.

- stainless steels such as 304  and 316  are also limited in their use for sulfuric acid media.

-Therefore, pump valves for transporting sulfuric acid are usually made of high silicon cast iron and high alloy stainless steel.

-Fluoroplastics have good sulfuric acid resistance, and using fluorine lined pumps is a more economical option.

2.Selection of Material for Hydrochloric Acid Medium Water Pump

-Most metal materials are not resistant to hydrochloric acid corrosion (including various stainless steel materials), 

and molybdenum containing high silicon iron can only be used for hydrochloric acid at 50 ° C and below 30%.

-Contrary to metal materials, most non-metallic materials have good corrosion resistance to hydrochloric acid, 

so rubber lined pumps or plastic pumps (such as polypropylene, fluoroplastics, etc.) are the best choice for transporting hydrochloric acid.

3. Selection of material for nitric acid medium water pump

Most metals are rapidly corroded and destroyed in nitric acid.

Stainless steel is the most widely used nitric acid resistant material and has good corrosion resistance to all concentrations of nitric acid at room temperature.

Therefore, when the medium is nitric acid, stainless steel should be selected as the material for the water pump.

For high-temperature nitric acid, pumps typically use titanium and titanium alloys as materials.

4. Selection of Material for Acetic Acid Medium Water PumpOrdinary steel can severely corrode in acetic acid at all concentrations and temperatures.

Stainless steel is an excellent acetic acid resistant material.

Molybdenum containing 316 stainless steel is also suitable for high temperatures and dilute acetic acid vapors.

Therefore, high temperature ，high concentration acetic acid or containing other corrosive media，

can select high alloy stainless steel water pumps or fluoroplastic water pumps .

5. Selection of material for alkaline medium water pump (sodium hydroxide)

-Iron and steel are widely used in sodium hydroxide solutions below 80 ° C with a concentration of 30%.

-Compared with cast iron, ordinary stainless steel has no obvious advantages in corrosion resistance to alkaline solution. 

As long as a small amount of iron is allowed to be added into the medium, stainless steel is not recommended.

For high-temperature alkaline solution, the water pump is mostly made of titanium and titanium alloy or high alloy stainless steel.

6. Selection of material for ammonia medium water pump (ammonia oxidation)

Most metals and non-metals have slight corrosion in liquid ammonia and ammonia water (ammonia hydroxide), 

so only copper and copper alloys are not suitable for use with water pumps in this medium.

7. Material Selection of Brine Medium Water Pump (Seawater)

The corrosion rate of water pumps made of ordinary steel is not too high in sodium chloride solution, seawater, and salt water.

Generally, water pumps must be protected with paint; Various types of stainless steel also have a very low uniform corrosion rate,

but may cause localized corrosion due to chloride ions. Therefore, it is generally better to use 316 stainless steel for water pumps in salt water.

By katreenipump