What are the reasons for pump shaft breakage?
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Recently, I came across online the statement that \"the common cause of shaft breakage is the pump operating for a long time in the high head and low flow rate range, which results in excessive radial forces on the pump bearings; therefore, it should be avoided to use the pump in such a range.\" This statement comes from \"Baidu Wenku, Slurry Pump PPT.\" I would like to know: 1. Does \"high head and low flow rate\" refer to conditions below the rated operating parameters or below the minimum flow rate? 2. Why is the radial force too high in this area? Is it because cavitation below the minimum flow rate causes vibration, which in turn results in large radial forces?
1. Below the highest flow rate. 2. It may be that the high pressure inside the pump chamber results in a large radial force; we have a pump with a designed head of 600 meters, but when the outlet valve is closed to reduce the flow rate, the pressure at the pump outlet rises to 7 MPa
1. Does \"high head and low flow rate\" refer to conditions below the rated operating point or below the minimum flow rate? In this article, it does not refer to values below the minimum flow rate; it could also be above that minimum flow rate. 2. Why is the radial force too high in this area? Is it because cavitation below the minimum flow rate causes vibration, which in turn results in large radial forces? It has nothing to do with cavitation; it is caused by the hydraulic radial force. The radial force is at its minimum at the design point, and it increases both when it is below or above the design point, with the increase being greater at low flow rates.