It can’t build pressure – please advise
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If it’s a motor issue, could that affect the water supply pressure? The make-up water pump doesn’t have pressure gauges at the inlet or outlet; the pump operates with normal sound, and a pressure change can be clearly felt at the exhaust port, which isn’t consistent with the situation where an impeller has fallen off. Only the electrical control room can monitor the current. Based on current estimates, if there is a problem with the motor, the current level should be low; however, things are not clear yet. We are waiting for the manufacturer to arrive. I’m quite interested in such issues, so I’d like to ask everyone for their opinions.
Based on our experience with the makeup water pump, a failure of the check valve is the most likely scenario. First, close the outlet valve, open the inlet valve, start the pump, and then quickly open the outlet valve. I hope this will be helpful to you.
The pump’s inlet is blocked; just check it and it will be fine.
There is no pressure gauge on the outlet; how do you open the outlet valve? Will the motor not experience overcurrent when operating? The operating point of a pump is the point where the pump’s characteristic curve intersects with the system’s characteristic curve. First, standardize the pipeline layout and install the necessary instruments. Relying solely on verbal descriptions of phenomena provides no basis at all.
For such single-stage pumps that are small in power, whether the valve in the inlet pipeline is blocked or not has less of an impact on the current. Moreover, if the blockage is not severe, the symptom is unstable outlet pressure, and the result of unstable pressure is a lack of compression. If it is used as a makeup fluid, since there is pressure at its outlet itself, the pump will certainly not be able to generate pressure if its pressure is lower than that of the system.
I wonder if it’s possible to open the inlet and outlet valves without starting the pump, in order to see if the pump rotates on its own; if everything is normal, then the inlet and outlet should not get blocked. Check whether the motor wiring has been altered and whether the direction is correct
It’s probably not a problem with the motor; check to see if the inlet is blocked. The medium used in such submersible pumps is usually not very clean.
1. Blockage at the front end of the water pump; this probability is generally low. 2. Pump blades are damaged. 3. There is gas remaining inside the pump, and in this case, the pump body heats up again. 4. The one-way valve at the pump outlet is stuck, which is also related to the presence of gas in the liquid.
In this case, the pump will reverse direction~~~~ If it reverses, will the lock nut of the impeller come loose?
Judging from the picture you sent, your pump seems to be a pipeline booster pump. Since you say it can’t build pressure, which means it worked fine before, that proves the pump is compatible with the piping, so there’s no issue with the selection. I don’t know what medium you are using; whether it tends to accumulate scale, and whether it contains impurities. All these factors can lead to a reduction in the flow channel of the impeller, affecting flow rate and pressure. All pipeline pumps have a specified installation direction, and there are also requirements regarding the rotation direction of the motor; if it rotates in the opposite direction, the impeller will eventually break off after some time.