Using relief valve as minimum bypass for centrifugal pump
Using relief valve as minimum bypass for centrifugal pump
(OP)
Hello,
I have a question about some set-ups that use relief devices as minimum bypass valves. On PD pumps, I understand why this is necessary since PD can overpressure the line or itself if blocked in. However, for centrifugal pump, it's unlikely pump will overpressure itself during shut-in (if that was possible then every start-up would be very scary for the operators).
So what are the benefit of using relief valves for minimum bypass? How would you determine the valve set pressure? On the other hand, what are the advantage for using a minimum bypass line instead of a relief valve?
If the current set-up uses relief valves, what are the incentives to use a minimum bypass line?
Thanks for your help.
I have a question about some set-ups that use relief devices as minimum bypass valves. On PD pumps, I understand why this is necessary since PD can overpressure the line or itself if blocked in. However, for centrifugal pump, it's unlikely pump will overpressure itself during shut-in (if that was possible then every start-up would be very scary for the operators).
So what are the benefit of using relief valves for minimum bypass? How would you determine the valve set pressure? On the other hand, what are the advantage for using a minimum bypass line instead of a relief valve?
If the current set-up uses relief valves, what are the incentives to use a minimum bypass line?
Thanks for your help.





RE: Using relief valve as minimum bypass for centrifugal pump
Good luck,
Latexman
RE: Using relief valve as minimum bypass for centrifugal pump
RE: Using relief valve as minimum bypass for centrifugal pump
Best regards
Morten
RE: Using relief valve as minimum bypass for centrifugal pump
A back pressure regulator works more reliably for longer.
These approaches are not foolproof but have the benefit of sending flow back to suction only when needed. That's handy when you have a pump whose minimum flow is a significant fraction of the operating point.
RE: Using relief valve as minimum bypass for centrifugal pump
RE: Using relief valve as minimum bypass for centrifugal pump
Alternatively you can install a bypass line with an orifice, as discussed above. I don't think there's a general answer for which is better. It depends on the specific application. A continuous bypass is simple and reliable, but the downside is that it wastes energy. However, if the consequences of failure are bad enough, then that msy be the right answer.
For small PD pumps, I think a PSV is the best solution.
RE: Using relief valve as minimum bypass for centrifugal pump