(1) Based on temperature, cold oil pump below 200℃, hot oil pump above (200.4000C);
(2) to distinguish between sealing oil, general hot oil pump sealing oil, and cold oil pump not.
(3) To distinguish by material, hot oil pump to carbon steel, alloy steel as the material, and cold oil pump can use cast iron
(4) It is distinguished by preheating. The hot oil pump needs preheating, while the cold oil pump does not.
Why should hot oil pump preheat?
Answer :(1) high temperature: the general temperature of hot oil pump is about 200-350℃, such as no preheating, cold pump body, hot oil after entering, because of the large temperature difference between cold and hot, will make the pump can not withstand this drastic change, causing leakage, cracks, parts damage and parts due to thermal expansion coefficient is not the same, so that the two parts swell and so on. 2) viscosity: hot oil pump transmission medium viscosity is very large, at room temperature and low temperature will be solidified, and even the pump pipeline condensation, resulting in not starting the amount, flow, head is small, and the pump vibration and noise.
Author: Gear oil pump
