Problem with gradual drop in oil pump pressure at the reciprocating machine shaft head? As shown in the figure.
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This post was last edited by Huang Zhao on 2017-3-16 at 16:13. The oil pump for the reciprocating machine’s shaft head maintains normal pressure at the start of each operation; however, after three hours of operation, the pressure drops from 0.32 to 0.18. The same situation occurs when the machine is started again. I’m wondering if anyone else has encountered a similar problem? Thank you! Such as the oil pump pressure curve diagram. Oil pump curve graphs for the last three startups.
Does our compressor seem to have this same problem as well?
As the oil temperature rises, its viscosity decreases! It is important to control the oil temperature, generally between 35°C and 45°C!
The oil temperature was mentioned above; also, there might be a leak in your oil circuit
Oil temperature, check the water cooling. A similar situation can occur when the oil temperature is too high.
Will the effect of oil temperature be that significant? The characteristic seems to be affected by oil temperature; the temperature can be controlled to verify this. It is also possible to check whether there are any issues with the pressure sensing element
How long has the device been in operation? Check the fit clearance of the working components to see if there is any increase in wear.
The oil temperature is normal, within the range of 38–40°C. The pressure sensing element has just been replaced with a new one, and there are no issues. As long as the speed and temperature of the gear pump, as well as the end-face clearance, are within the standard ranges, there will be no fluctuations once circulation is established; and if any fluctuations do occur, they are minor. In the current situation, we suspect that the inlet seal is not tight, allowing air to enter the lubricating oil at the inlet, resulting in a small amount of air in the oil. When the compressor stops running, air is released from the lubricating oil; therefore, after 7–8 hours, the pressure returns to normal once the compressor is started up again. Over time, however, the oil pressure drops again.
The outlet pipeline of the shaft head pump should be equipped with a vent that leads back to the machine’s oil sump, so that air can be expelled; you might want to give this a try
Let’s check whether the safety valve at the oil pump outlet is leaking internally. Our facility never has such safety valves calibrated, as they aren’t considered pressure vessels after all. Several units experienced low oil pressure due to internal leakage in the safety valves