For centrifugal pumps, various material can be used in manufacturing the pump but based on different situations. The common material you can choose as follows:
A. Cast iron
1. Gray cast iron
It is the most commonly used type of cast iron, and its national code is HT. Generally, the pump body, impeller, pump cover, suspension, etc. of the net water pump are made of this material, and three grades are usually used: HT150, HT200, HT250. For the non-main parts such as the base and the pad, the HT150 is mostly used, and the HT200 is used for the pump body, the pump cover, the suspension, etc., and the HT250 is used for the impeller, the ring ring and the bushing.
Countries have different representations of gray iron, such as Japan: FC, Germany: GG, and the United States: Class.
2. Ductile iron
It is a kind of cast iron with better comprehensive function, and the national code is QT. Because its mechanical function is close to steel, and its forging function and processing machine are superior to steel, it is usually used as a substitute for cast steel. The most commonly used brands are: QT450-10, QT500-7, QT600-3.
There are also corrosion-resistant cast iron - high silicon cast iron, wear-resistant cast iron - white cast iron, high toughness cast iron, malleable cast iron and so on.
B. Cast steel
Because the strength of cast steel is high, usually when the pressure is >1.6Mpa, the pressure-bearing parts are mostly cast steel, the national standard code is ZG, and the most commonly used grade is ZG230-450.
Japan and the United States usually use CS to represent cast steel.
C. Stainless steel
The most widely used stainless steel is austenitic stainless steel, such as 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti and the like. In addition to a small amount of medium such as hydrochloric acid and dilute sulfuric acid, austenitic stainless steel is an excellent corrosion-resistant material and 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 codes for Japan and the United States are SS420.
In addition, high alloy stainless steel (20 alloy) and double stainless steel are also ideal corrosion resistant materials.
D. Alloy steel
The most representative alloy steel is 40Cr, which is commonly used for high strength pump shaft materials.
E. Carbon structural steel
Usually 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 for pump shaft materials without erosion requirements.
F. Non-metallic materials
Non-metallic materials for pumps are mainly used for sealing, such as PTFE, fluororubber, nitrile rubber, etc. Among them, PTFE is used for chemical pump seals and mechanical seals due to its excellent corrosion resistance and high temperature resistance. It is used in almost all chemical media at 250 °C. Its disadvantages are high hardness and assembly difficulty. Big.
Fluororubber is also a good temperature and corrosion resistant material. The upper temperature limit is 160 °C. When the user has no special requirements, the company's chemical pump uses the sealing ring of the material; while the nitrile rubber is mainly used for oil resistance. Or a static seal when purifying the medium.
