The liquid level in the tank of the self-priming pump cannot be maintained; it needs to be refilled frequently
Thread Content
Help: Self-priming pump for the waste water cooling tank; the medium is boiler drain water. It should start and stop automatically in response to the liquid level in the waste water cooling tank； It has been operating well since it was put into use in 2017, with little need for manual operation. However, starting in April 2022, its performance declined; the self-priming tank often ran out of liquid, causing fluctuations in the outlet flow rate, which led to the pump having to be stopped manually. The flow rate could only be stabilized after the pump was refilled. Fearing blockages in the pipelines and the self-priming tank, high-pressure water cleaning was performed on various locations including the inlet pipelines and the self-priming tank, but it was ineffective ； In addition, each sealing point from the inlet to the outlet was checked for air leaks, and all gaskets were replaced. When adding water to the tank, a significant negative pressure can be felt inside it; air is drawn in, but the liquid level in the tank still cannot be maintained. I am reaching out to the experts on this forum to see if anyone has encountered a similar situation; they might be able to help identify the cause of the problem. At present, I have to refill the self-priming tank almost every day, which is quite troublesome. I’d like to thank you in advance!
Check the liquid level to see if it’s not sensitive!
It should be an electrical issue related to the interlock relay of the instrument. The level gauge interlock switch should be checked or replaced. For reference.
Check the bottom valve; foreign objects may be stuck in it, causing partial blockage or corrosion, which can lead to poor sealing and subsequent leakage downward after the pump stops running.
Normally, it starts and stops in an interlocked manner based on the liquid level of the wastewater cooling tank. Why does it keep running even after the low liquid level has been reached? Reset the low liquid level interlock.
It’s the self-priming tank at the pump inlet that’s empty, not the pool
Our inlet pipeline doesn’t have a valve; it goes directly to the inlet of the pump’s self-priming tank
The most likely cause is a problem with the level gauge, which leads to vacuum formation and prevents the pump from stopping automatically；
A unified response: What was monitored was the liquid level of the self-priming tank, not that of the sewage cooling tank; perhaps my previous explanation wasn’t clear enough
Is the suction line of the siphon tank corroded, and is there no height difference between it and the outlet line of the siphon tank?