3 replies to this topic

[Process_engg94]

What is significance of shutoff pressure ?
Why it is defined only for centrifugal pump but not defined for Positive displacement pump ?

Thanks in advance.

[latexman]

It is a natural upper pressure operating limit for centrifugal pumps, and easily identified on the pump curve at zero flow.  Sometimes, shut off head is useful to determine  a pump's impeller size.

 

Many, but not all, PD pumps do not have an upper pressure operating limit if one blocks the discharge line.  The discharge pressure will increase until something breaks.  On those, one needs protection, like a PSV, rupture disk, or something similar.

[fallah]

What is significance of shutoff pressure ?
Why it is defined only for centrifugal pump but not defined for Positive displacement pump ?
 

 

Hi,

 

Significance: To specify the PAHH (Pressure Alarm High High) at the pump discharge, and, to specify the design pressure of the discharge line and downstream facilities...

 

The reason of not to be defined fro PD Pumps: For PD Pumps the discharge pressure is almost unlimited (to be raised by raising the destination pressure) hence there is no specific shut off pressure. This unlimited discharge pressure will mostly be limited by putting a PRV at discharge line to be set at the design pressure of the discharge line and downstream facilities...

Edited by fallah, 25 April 2022 - 10:43 PM.

[breizh]

Hi,

I do believe Process_engg94 is in need of some literature about  pump :

Pump system articles (pumpfundamentals.com)

Mc Nally Institute – Pump, centrifugal pumps, PD pumps, seals & mechanical seals data

 

Good luck

Breizh