6 replies to this topic

[fro054402]

Anyone could help me to determine pressure drop caused by a centrifugal pump on stand by condition.

There is a vessel in pump suction (press: 6 kg/cm2) and a vessel in discharge side (press: 8 kg/cm2). If there is a failure in that pump and we recommend to increase the pressure of the vessel on the suction to 7,5 kg/cm2 and decrease the vessel pressure on discharge side to 5,5 kg/cm2 to let the fluid flows as much as it could flow without pump. 

Is there any method to calculate the flow or determine pressure drop of pump (not running and the suction & discharge valve fully opened).

Thanks in advance.

[samayaraj]

Why cant you introduce a bypass line across the pump with a control valve? During pump failure, you can continue the flow through bypass line.

[fro054402]

Why cant you introduce a bypass line across the pump with a control valve? During pump failure, you can continue the flow through bypass line.

That's what we are going to do. We need a justification to modify the system. So that we have to make a calculation about all possibility before deciding to add the by pass line. Do you have any idea about the calculation?

[breizh]

Hi ,

Why not buying a spare pump ?

my 2 cents

 

Breizh

[samayaraj]

I don't think there are calculations available for finding pressure drop across pump. In your case, if pump stops, it will take some time to pressurize suction vessel and depressurize discharge vessel and you need additional compressor/ pressurizing setup etc etc and makes the system complex. As Breizh said, why can't you introduce a standby pump? This will solve your problem simply. The option you choose seems complex.

Edited by samayaraj, 05 November 2015 - 09:54 PM.

[fro054402]

I don't think there are calculations available for finding pressure drop across pump. In your case, if pump stops, it will take some time to pressurize suction vessel and depressurize discharge vessel and you need additional compressor/ pressurizing setup etc etc and makes the system complex. As Breizh said, why can't you introduce a standby pump? This will solve your problem simply. The option you choose seems complex.

Thanks for the advice...formerly i wonder there is method to calculate the flow when the pump idle..okay then, so there is no other consideration to add the by pass line. 

[Bobby Strain]

You could always try flowing through the pump. It is low head, so flow resistance should not be too great. And, you haven't indicated the flow required.

 

Bobby