Dielectric properties and material selection of pump

The basic requirement for a successful pump device is performance and lifetime. Performance is the pump parameters: head, flow and efficiency. Life is the total number of hours in which one or several parts have to be replaced before the performance is maintained. Is mainly in the actual operating conditions of structural materials to resist corrosion. Erosion or a measure of the combination of these two.
In the process of selection of pump components materials, you need to consider factors; user experience, is expected to pump life (such as for short-term or long-term use), intermittent or continuous use, pumping hazardous or toxic liquid or liquid condition. The corrosive liquid of a liquid is different from one or more of the following conditions: temperature, concentration, and temperature. Purity and speed. In solid and gas. Usually refers to the chromium content of stainless steel
The addition of Fe based corrosion resistant alloy 12%~30% can influence and change the microstructure and properties of the alloy. According to the different carbon content, the 18% chromium stainless steel can be divided into three categories. Ferrite steel, which is less than 0.08% carbon, and 0.08%~0.22% carbon austenite ferrite steel and austenitic steel more than 0.22% carbon.
Selection of materials due to the consideration of the problem:
1) the corrosion of the medium: the corrosion resistance of the material to the medium has a certain range of. For example, 1Cr18Ni9 resistance, dilute concentrations of nitric acid or organic acid corrosion. But not resistant to dilute sulfuric acid, hydrochloric acid corrosion.
2) electrochemical corrosion; the same metal material is best used in the whole flow channel of the pump.
3) the medium temperature: the material is brittle at very low temperature. In the high temperature creep corrosion will produce a medium; the ability of a material at room temperature. But not necessarily resistant to high temperature of the medium of rot
Corrosion; therefore, the material properties should meet the requirements of the transmission medium temperature.
4) economy: the materials are different, the price of the machine and the machining performance are not the same, so in several materials at the same time to meet the corrosion. Temperature requirements, should choose the price is relatively cheap, machining
Good performance material.
5) the wear of the solid particles: the medium containing abrasive particles, the wear resistant materials should be used.
6) bite material; for relative movement of the parts, such as shaft and shaft sleeve. Bolt and nut, impeller sealing ring and pump body seal ring, etc., in the selection of materials should make the hardness of the parts of some differences, or in the handling and operation of easy to bite each other.
7) the size of temperature of the same part: when the same parts of the temperature difference is large, as in high temperature liquid transfer pump cover and the pump cover and the cooling medium contact temperature expansion, and cooling
The temperature of the water contact is small, so the parts should adopt the material with good plasticity, so as to avoid the crack caused by the expansion of the movement.
8) need to weld parts: in the casting, processing and use process need to repair welding parts of the application of good welding materials, such as low carbon steel welding is better than high carbon steel
9) the single stage head is very high: the single stage head is very high, the liquid flow rate is very high, over flow components should use the high strength steel, such as precipitation hardening stainless steel.