The centrifugal pump does not deliver flow
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Centrifugal pump: low current when turned on, no pressure at the outlet; no flow detected. The pressure at the inlet side of the pump is 0.01 MPa, while the pressure at the outlet side is 0.4 MPa. The pump’s head is 50 meters
This post was last edited by CHANGBAISHI on 2020-4-11 07:45. This question is too general. There is no pressure at the pump outlet – is it the pressure before the valve when the pump outlet valve is closed? If not, it may be that there is no water in the system’s piping equipment; this kind of phenomenon occurs when the valves are opened too wide. It is an operational issue. If no pressure builds up in front of the valve when the outlet valve is closed, it indicates that the impeller may have fallen off or the shaft may be broken. It’s better to provide a more comprehensive overview of the relevant phenomena at the scene, to facilitate discussion and reduce unnecessary speculation. For reference. The correct way to start a pump is to gradually open the outlet valve while ensuring normal pressure in the pump. However, the pump’s proper operation cannot be determined by the valve opening degree. The valve opening should be such that, at the normal pressure at the pump outlet and with the maximum rated current, the pump is in its normal operating condition. However, under special production conditions, while ensuring the pressure, the pump’s outlet valve can be closed to a smaller degree, but this must not cause the pump body to overheat.
Theoretically, the causes are gas entrapment and cavitation； In terms of practical operation, it is necessary to check whether the two causes have been eliminated: whether the inlet is open, whether the inlet filter is clogged, whether the inlet pressure meets the design requirements, and whether the outlet valve is open, among other things.
There is air at the inlet, the temperature of the medium at the inlet is high, the inlet pipeline is not unobstructed, the valve is not open, or the filter is clogged.
Check whether the pump inlet valve is open, and clean the inlet filter
What medium? What is the saturated vapor pressure? What is the net positive suction head of the pump?
1. There is a problem with the pump. 2. There is a problem with the operation. 3. There are issues with the on-site process parameters
It’s definitely due to insufficient liquid flow; before starting the pump, it’s necessary to fill it and release air from it, and check the inlet filter! Another issue is the detachment of the valve disc in imported valves; this happens very rarely, but we have experienced it once!
Also, the clearance of the impeller mouth ring is severely worn!