The advantages of PPS material applied to chemical pumps

Corrosion resistant pumps are essential machinery and equipment used in the chemical industry to raise and transport organic chemical media, and corrosion is the most difficult problem for chemical machinery and equipment. If the design scheme is used improperly, the light damage to machinery and equipment, or cause accidents. Chemical machinery and equipment damage basically 60 ~ 80% is caused by corrosion, so in the selection of corrosion-resistant pump models to pay attention to the science of material selection. Let's understand the key points of chemical pump material selection.

Sulfate is a highly corrosive medium with a wide range of uses. Sulfuric acid concentration and temperature make a big difference in the corrosion of materials. When the concentration is greater than 80% and the temperature is less than 80 ℃, carbon steel and cast iron have good corrosion resistance, but it is not suitable for high-speed flow of sulfuric acid, not suitable for pump valve materials; 304, 316 and other ordinary stainless steel for sulfuric acid media also have restrictions. Therefore, the pump valve of sulfuric acid pump is generally made of high silicon iron (casting processing difficulties) and high alloy stainless steel (alloy 20).

Most metallic materials are not resistant to hydrochloric acid corrosion (including various stainless steel materials), and ferrosilicon with high molybdenum content can only be used for hydrochloric acid at 50°C and below 30%. Compared with metal materials, most non-metallic materials have good resistance to hydrochloric acid corrosion. For example, PPS engineering plastics are not subject to corrosion of most acids and alkalis, chemical stability close to polytetrafluoroethylene, in the role of long-term working load and thermal load can still maintain high mechanical properties and dimensional stability. Therefore, polyphenylene sulfide PPS has great material advantages for use in the manufacture of chemical pumps.

When considering corrosion resistance for chemical pumps, it is important to note that no one material is a panacea, and there is no one material for all fluids in organic chemical production processes. Materials that have the ability to work with a wide range of corrosion resistance are considered ideal for corrosion resistance.

• Chemical valves
• What are the test pressure methods of commonly used industrial valves?