First, cast iron
Gray cast iron is the most commonly used type of cast iron, the national standard code is ht. Generally, the pump body, impeller, pump cover, suspension, etc. of the clean water pump (diesel water pump) use this material, three popular brands: ht150, ht200, ht250. Ht150 is used for non-main components such as base and gasket, ht200 is used for pump body, pump cover, suspension, etc. ht250 is used for impeller, ring, bushing, etc. The expression patterns of gray iron in different countries are different. For example, the Japanese code is FC, the German code is gg, and the US is first class.
Ductile iron is a cast iron with better overall performance. The national standard code is QT. Because its mechanical properties are close to steel, its casting properties and processing properties are superior to steel, so it is often used as a substitute for cast steel. The most commonly used brands are QT450-10, QT500-7, QT600-3. Due to the limitations of casting, etc., the impeller of the pump is currently used with materials, and the cutting open impeller has superior cost performance. The DIN standard for ductile iron is GGG, and the United States is ductile iron.
In addition, there are corrosion-resistant cast irons – high-silicon cast iron, wear-resistant cast iron – white cast iron, high-toughness cast iron – malleable cast iron. Due to some difficulties in processing, many products will not use these materials.
Second, cast steel
Due to the high strength cast steel, usually when the pressure is larger than 1.6mpa, the pressurized component is cast steel more, the national standard code name is zg, the most common brand is zg230-450. Japanese and American will use cs normally
Third, stainless steel
The most widely used stainless steels are Austenitic stainless steels such as 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti. Austenitic stainless steel is an excellent corrosion-resistant material in addition to small amounts of media such as hydrochloric acid and dilutes sulfuric acid. It is the most commonly used corrosion-resistant material for chemical pumps. Japan and the United States usually use SS304, SS316, SS316L to represent Austenitic stainless steel. Martensitic stainless steels such as 2Cr13 and 3Cr13 have better mechanical properties than Austenitic stainless steels and are commonly used as materials for pump shafts and bushings. The corresponding code for Japan and the United States is SS420. In addition, high alloy stainless steel (20 alloys) and double stainless steel are also ideal corrosion-resistant materials.
Fourth, carbon structural steel
Generally divided into ordinary carbon structural steel and high-quality carbon structural steel. The most representative ordinary carbon structural steel is Q235, which is widely used in various steel plates and sections. The most representative high-quality carbon steel is 45 steel, which is widely used in pump shaft materials without corrosion requirements.
Fifth, alloy steel
The most representative alloy steel is 40cr, which is commonly used for high strength pump shaft materials.
Six, non-metallic materials
Non-metallic materials for pumps are mainly used for sealing, such as PTFE, fluoro rubber, nitrile rubber, and the like. Among them, PTFE is used for chemical pump sealing and mechanical sealing due to its excellent corrosion resistance and high-temperature resistance. It is suitable for almost all chemical media at 250℃. Its disadvantages are high hardness and difficulty in assembly.
Fluororubber is also a good temperature and corrosion-resistant material. The upper-temperature limit is 160℃. When the user has no special requirements, the chemical pump recommends the Fluororubbe sealing ring; the nitrile rubber is mainly used for the static sealing of oil or water-resistant media.