The oil pump in the smoke extractor inlet butterfly valve’s hydraulic control system starts up frequently on its own
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Dear colleagues, recently the oil pressure control system for the butterfly valve at the inlet of the flue gas extractor in our company’s catalytic units has been losing pressure quite rapidly; within about ten minutes, the system’s oil pressure drops from 10 MPa to 6 MPa, after which the oil pump starts up automatically. No oil leakage was observed at the scene either. May I ask what the automatic start-up cycle for the oil pumps in each of your units is?
Which is the valve manufacturer? It would be best to have the corresponding oil pressure control circuit diagram available for reference! By the way, does your hydraulic control system have an accumulator? Is there any damage to the nitrogen bladder inside the accumulator!
It doesn’t seem to have much to do with damage to the air bag of the accumulator, right?
It’s not clear which type of butterfly valve you are using; all of them come with flow diagrams. Please check each valve from the beginning, especially to see if the pressure relief valves are leaking or damaged
At the inlet of the smoke extractor, Lanlian. I also suspect that the pressure in the air bag of the accumulator might be low
Are you dealing with servo valves, or proportional valves? Is the valve position stable?
Ageing of the internal membrane can also cause the pressure to not reach the required level! We have encountered such situations here!
This post was last edited by lupg on 2017-8-17 at 16:05. 1. The original poster did not provide a hydraulic circuit diagram, so only guesses can be made here. 2. In the hydraulic flow, there are two paths by which the hydraulic oil returns to the tank: 2.1. It returns to the tank through a valve after passing through the cylinder; 2.2. The hydraulic oil returns to the tank via the pressure relief valve at the pump outlet. 3. When hydraulic oil passes through the cylinder, the valve will operate; if the valve does not operate, it indicates that the pressure relief point is not in this circuit. 4. The pressure relief valve at the pump outlet serves to maintain a constant system pressure, and it opens only when the pressure exceeds the set value. However, based on this case analysis, it is possible that the pressure relief valve did not return to its proper position, resulting in a slight internal leak that caused a drop in system pressure. 5. As long as the valves are properly sealed, there is no such thing as a self-starting cycle for the oil pump ； If a leak occurs, the frequency of the pump’s automatic startup is determined based on the amount of leakage
Check if there is a problem with the pressure relief valves; there are two of them!
Could you share the troubleshooting steps? Learning*, thank you.