Two condensate pumps, with a temperature of 80-90; pump type IS, single-stage single-suction, and they do not deliver any flow. Help, how to solve this?
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There are two condensate pumps; the temperature is 80–90 degrees. The pump type is IS, single-stage, single-suction, and they are used to pump condensate water. The inlet and outlet pipelines are shared. One of the pumps operates normally, while the other functions properly when the outlet valve is closed. However, flow does not occur once the outlet valve is slightly opened. Even if the pump that is operating normally is stopped and both the inlet and outlet valves are closed, flow still does not occur in the pump that is being used. I checked the pipeline, impeller, and rotation direction – everything seems fine, but the flow rate isn’t increasing. Mizusuke, how to solve it?
This situation may be caused by the following issues: 1. Air entering the system: Check the pump’s sealing system to ensure there are no leaks, especially at the pump’s water intake end. 2. Blockage or partial obstruction in the suction pipeline: Clean the suction pipeline to ensure unobstructed water flow. 3. High resistance at the outlet valve or in the pipeline: Check whether the valve is not fully open or if there is any blockage in the pipeline. 4. Internal wear or damage to the pump: Inspect the internal components of the pump, such as the impeller and seal rings, to check for any wear or damage that may require replacement. 5. NPSH issue: Check for any problems related to insufficient net positive suction head (NPSH). It is necessary to ensure that the pump’s available NPSH (NPSHa) is greater than the pump’s required NPSH (NPSHr). 6. Pump and drive mechanism assembly issue: Verify that the connection between the pump and the motor is correct, with no misalignment or looseness. 7. Insufficient air intake for the pump: Ensure that the pump’s water inlet has an adequate flow of water and that the flow is steady, with no vortices or air absorption occurring. First, the aforementioned issues should be systematically ruled out. If none of these are the problem, then issues related to system design may need to be considered, such as improper system layout or selection of operating points. If you are unable to resolve the issue on your own, it is recommended to contact professional pump technicians for inspection and adjustment. .
Have the inlet and outlet pipes been checked? The inlet pipe is too small; the liquid temperature is high. When both pumps operate simultaneously, the flow rate of water is too fast, causing vaporization. As a result, the pumps can no longer function properly.
The water inlet pipeline was rerouted, with two separate paths leading to the pump； Check the impeller mouth ring clearance
It’s possible that there is a foreign object in the flow channel of the volute. We have a high-speed pump here that is also used to pump condensate; some slag has blocked the flow channel, preventing the pump from functioning properly.
1. Check whether the outlet passage is unobstructed, such as whether the outlet passage of the volute is blocked or whether the valve core of the outlet valve has fallen off, etc. 2. Check whether the impeller is installed in the wrong direction, whether the motor is rotating in the reverse direction, and whether there are any issues with the impeller. 3. If everything else is fine and the two pumps are swapped but the flow rate still isn’t sufficient, then it’s a process-related issue; the problem needs to be identified by examining the process parameters