Open the inlet valve of the multi-stage pump to start it up
Thread Content
Due to reasons related to production and the equipment itself, for an 8-stage multi-stage centrifugal pump, if the operator starts the pump with the inlet valve at normal pressure, what effects will this have on the pump? Will it cause faster wear of the balancing device?
Generally, centrifugal pumps are required to be started with the inlet fully open; I’m not sure why the pump in the original post was started with the inlet blocked Were there any abnormalities when the pump was started in this way?
It is prone to voids, resulting in axial movement, which affects both the balance disk and the balance hub. It is recommended to fully open the inlet valve and start the pump.
The biggest drawback is the tendency to experience cavitation; once cavitation occurs, the inside of the pump becomes chaotic and various problems arise. It is recommended to avoid pushing the pump to its limits, as this can lead to serious failures
I agree with the opinion of the moderator above. Furthermore, it’s not only the pump itself that is prone to the aforementioned problems; since you mentioned it’s an 8-stage multi-stage pump, this means the pressure is high (take, for example, the boiler feed pumps we use here). If you block the inlet valve, there’s a high chance of internal leakage from that valve. By the time various faults arise in the pump due to the blocked inlet valve, it will no longer be possible to close the inlet valve properly, and then it will be difficult to repair the pump! ! ! Therefore, it’s better to change the operators’* habits at the source: keep the inlet valve fully open, and use the outlet valve, variable-frequency output, control valves, and their auxiliary lines to carry out adjustments
The last edit to this post was made by I believe LEE on 2019-4-18 at 17:06. Yes, it’s easier to operate the inlet valve at the current position, while the outlet valve is more difficult to control; operators simply choose the one that is easier to use
I’ve emphasized this to the workshop staff and those on the job multiple times, but it hasn’t worked:(
I’ve said it over and over again: the positions aren’t followed according to the procedures, and the workshop isn’t well-managed either. . .
What’s more, the pump that was originally used for pumping water can experience changes in its operating conditions and end up being used to pump slurry. The workshop says there’s nothing they can do about it; this situation really gives us a headache:dizzy:
Do you have the authority to assess? If so, go ahead and do it. Persuasion is useless; it won’t work.
This post was last edited by 3983596_FPPZ on 2018-10-31 at 10:52. It is suggested that the original poster, in line with the scope of their role and responsibilities, and following the principle of doing one’s duty according to one’s position, identify several issues related to improper use of the equipment, as well as the possible consequences and safety risks involved, and propose solutions for addressing these issues. Such information should be reported to management via email so that it can be traced back; otherwise, it’s better to stay silent. The management will surely make the right judgment. And when you have time, please post more messages in this section and answer more questions – it would be a shame to waste such talent. Thank you very much.