6 replies to this topic

[Takechi]

Dear all expert

 

When I see the performance pump curve, I cannot see the mimumum flow line of positive displacement performance pump curve.

 

Does positive displacement pump require minimum flow for protect temp rising or vibration? Why?

 

 

Sapao

[fallah]

 

Does positive displacement pump require minimum flow for protect temp rising or vibration? Why?

 

 

Sapao,

 

No, because a PD pump is a constant flow machine. To protect downstream piping /equipment against high pressure a PSV is applied at pump discharge line.

[Takechi]

Fallah

 

Gear pump or screw pump also the same, right? It does not require minimum flow.

 

Salapao

[fallah]

 

Gear pump or screw pump also the same, right? It does not require minimum flow.

 

 

All PD pumps...

[farid.k]

But pd pump has recycle line that has backpressure regulator in order to make sure the system will not over pressure. It act just like minimum flow line. The difference is minimum flow line to protect pump to not operate the below minimum flow line, but pd pump is to protect to not over pressure at discharge side. Both line normally will go back to reservoir

Edited by farid.k, 12 October 2018 - 10:48 AM.

[Takechi]

Thanks for you sharing Fallah, farid.k.

[breizh]

Hi,

Probably good to read this article:

https://www.pumpindu...au/pump-school/

 

Breizh