The outlet pressure of the centrifugal pump is unstable, and the liquid level cannot be lowered
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Our pump is used in chlorate decomposition tanks, and there is a constant issue of unstable pressure at the pump’s outlet – once the outlet is set to its maximum setting, no pressure is left. Is this caused by cavitation? How can this problem be resolved, either with the pump or the piping?
The description is unclear, making it difficult to judge. But it seems that the pump’s head may not be sufficient; please provide a detailed description of the operating conditions.
If the pump is too small and the outlet is set to its maximum flow rate, the pressure will be low, and thus it won’t be able to meet the head requirement of the application.
Should the pressure gauge be installed between the pump and the valve or in the pipeline behind the valve? If it is installed between the pump and the valve, the system resistance is low; in such a case, overloading may occur
1. The pump is too small; as a result, the flow rate is high and the pressure is insufficient. 2. It’s possible that suction isn’t working properly, which can be determined by examining the pipelines on site and the temperature of the medium
The medium is chlorate; it is being considered whether a large gap between the impeller mouth ring of the pump casing and the volute mouth ring, resulting from corrosion, is the cause of the pump not being able to deliver fluid
Why turn it up to maximum? Just set it to the level you requested at that time; if it’s not enough, then the product is defective
It is very likely that cavitation will occur at the maximum outlet flow rate; moreover, which is greater, the back pressure at the pump outlet or the head?
Is the inbound traffic restricted? Salt formation or filter clogging, etc
When a centrifugal pump is operating at its rated conditions, why is it necessary to open the outlet to its maximum? Opening the outlet too wide can also cause overcurrent and heating of the motor； It is possible to determine whether cavitation is occurring by listening to the sounds at the site ； The outlet pressure is unstable; could it be that the return line is too close to the pump’s suction inlet? The high return pressure causes vortices in the inlet line, leading to unstable pressure.
1. Did the unstable pressure and lack of increase in output you mentioned appear suddenly, or was it a problem that arose after a certain maintenance task? One factor to consider here is the possibility of the pump reversing ； 2. If this situation develops gradually, it is necessary to carefully analyze the relationship between fluctuations in pump inlet pressure and the occurrence of the problem. A common scenario is that during operation of the pump, the inlet pressure suddenly drops, resulting in cavitation; if the valve opening is increased further at this point, it will only exacerbate the cavitation. Next time this problem occurs, consider reducing the opening degree of the outlet valve; once pressure builds up, then increase the valve opening degree again.