The outlet valve of the liquid oxygen pump shuts off instantly; it is impossible to rotate the pump shaft after it stops operating
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This post was last edited by hxm2087 on 2012-2-5 09:22; the pump outlet pressure rose to 8.90 Mpa due to the sudden closure of the oxygen pump outlet valve. At a design pressure of 8.5 Mpa, the pump’s return valve opens fully automatically; however, cavitation does not disappear even after the outlet is opened. The pump cannot be rotated after it is stopped, and it still cannot be rotated even after heating is complete. It is suspected that the seal has seized – could anyone help analyze what might be the cause?
Experts, please share your opinions – could there be problems with the bearings and impellers? I will share the manufacturer’s test results with everyone......
The bearing is damaged; replace it. :)
This post was last edited by hxm2087 on 2012-2-22 at 22:35. The information provided by the original poster is insufficient; could it be more detailed?
If the vehicle won’t turn, then the bearings must have burned out
What is the structure of this pump? Could the original poster provide more details? I think the possible failure points are as follows: 1. Bearing failure ； 2. Bearing failures cause an increase in the radial runout of the impeller shaft, leading to frictional locking between the impeller and the volute ； 3. In the case of a labyrinth seal, an increase in the radial runout of the impeller shaft may also cause the seal to stick ；
Could the question be made more specific?
When the outlet valve closes suddenly, the pressure rises instantly, which causes a large amount of liquid oxygen to vaporize. This can lead to the vaporized oxygen mixing with the sealing gas, resulting in the sealing gas freezing and thus preventing rotation. In such a situation, you can try rotating it in the opposite direction to see if it moves; if it won’t rotate in the normal direction, do not force it to rotate, as this could result in it getting stuck in that position. Another issue could be related to the bearings – if the radial displacement of the bearings increases suddenly, it changes the gap between the bearings and the housing, and friction may occur. Also, check whether the shaft sleeve is misaligned; if it is, drill holes at appropriate positions on the shaft sleeve and insert plugs there
Heat the oxygen pump to room temperature and see if it can be rotated manually
The pump is completely damaged; the seal, impeller, and bearings are all damaged to varying degrees. I’ll send over the inspection report if I get the chance.................
Could the poster explain in detail why the outlet valve of your pump suddenly closed? In this case, the check valve should be able to fully protect the pump’s pressure safety. Is it because the logic of the pump isn’t well-designed enough!