The flow rate of the mass flow meter is unstable
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Our facility has a mass flow meter. If the pump operates automatically, the flow rate fluctuates greatly, but when the pump is operated manually, the flow rate remains stable. What is the reason for this?
Based on your description, the table seems fine; it’s possible that resonance is occurring
What does automatic and manual operation of a pump mean?
May I ask, is this pump controlled by an inverter?
It’s not variable-frequency control; there is no inverter
Automatic operation of the pump means remote start controlled by the DCS, while manual operation means start on-site
Check whether DCS has set different PID control schemes in remote startup. We generally do not use the DCS to start the pump; while the DCS may allow for starting, the pumps must always be started on-site, and they can be stopped using the DCS.
This post was last edited by libingtaoff8 on 2017-3-4 14:01. I’ve never seen DCS start up like this! Generally, for large machine repair oil pumps and water pumps, the interlocking system is set to automatic mode! When starting the pumps, they are started on-site; the standby pumps are activated via interlock automation, while all other pumps are started on-site. Where will you use your pumps?
Is the pump flow rate itself controlled by a control valve? If so, flow rate fluctuations are normal
It seems to be caused by improper PID parameter settings