Centrifugal pump pressure drop
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For a centrifugal diesel pump in the newly installed unit at our factory, when the inlet is fully open and the outlet is opened just a little more, there is severe pressure drop. Could it be that the material supplied at the inlet is insufficient? The selected size is too large
Check whether the diameter of the inlet pipe is too small or if it is blocked, and see if there are any foreign objects below the pump’s outlet flange, such as bolts
Clean the inlet filter to ensure unobstructed flow
This indicates that the back pressure in your system is insufficient; as the valve opens further, the system resistance decreases, which causes the pump’s operating curve to change and the flow rate to increase, until the motor experiences overcurrent and shuts down or gets damaged.
Removal of the filter screen from the inlet T-filter.
The poster could provide more detailed information such as specific pump models, parameters, operating conditions, pipe diameters, etc., for verification
1. The outlet diameter is too large. II. Insufficient inlet water flow; the pipes are too small and not compatible with the pump.
{:3_46:} I don’t know what the back pressure is. . I need to find out about it first
It’s obvious that the pump isn’t delivering the desired flow rate. You can check whether one of the following issues exists: 1. The suction line or inlet filter is blocked, or the filter mesh has too fine pores (the diameter of the filter holes is too small). Solution: Clean the suction line and filter, or replace the filter. 2. There is gas inside the pump, or the diesel is at a high temperature causing it to vaporize. Solution: Refill the pump and remove the gas from inside it (release air from the highest point before the pump’s outlet valve), ensuring that all gas is removed. Also check whether there are any leaks in the flanges of the suction line. 3. The motor is running in reverse. Solution: Contact the electrical team to reverse the motor’s direction of rotation. 4. The clearance between the impeller rings is too large, the impeller is damaged, or the impeller’s flow channels are blocked. Solution: Contact the maintenance team to inspect the pump, reduce the clearance between the rings, replace the impeller, or clean the impeller’s flow channels. 5. Check whether the liquid level in the storage tank or tower is below the pump’s suction height. Solution: Wait until the liquid level in the tank or tower rises before attempting to run the pump again. 6. There is no fluid or no pressure in the pump’s outlet line. Solution: In this case, the pump may still not deliver the desired flow rate. Turn on the pump until the pressure gauge shows the designed flow rate; then open the outlet valve slightly. This will cause the pressure gauge reading to drop. Listen for sounds indicating that fluid is flowing out. Wait until the outlet line is filled with fluid, after which the pressure gauge reading will increase naturally. Then adjust the outlet valve according to the system’s requirements to control the flow rate. 7. Another pump that shares the same inlet pipeline with it is currently in operation. The solution is to start that pump, keep its outlet closed, close half or two-thirds of the outlet of the other pump (this can be done if the system’s flow rate permits), and then open the outlet of this pump. The reason is that the inlet flow rate is low; the pump that is already in operation competes with this pump for flow, so it is recommended to increase the diameter of the inlet pipeline.