8 replies to this topic

[Ghasem.Bashiri]

As some general rule it is proposed to use following formula for shutoff calculation in centrifugal pump.

Why we need such conservative rule (See attachment).

 

I mean "Suction design pressure" + 1.2 * Pump head

 

Why we should have pump "design pressure" condition during pump discharge blockage and head rise. 

Edited by Ghasem.Bashiri, 06 December 2023 - 10:55 AM.

[latexman]

If not, the pump could be blocked in and run for a long time, the pumpage will heat up, and could possibly cause safety issues.  What is the pumpage?  A monomer or volatile chemical?

[fallah]

As some general rule it is proposed to use following formula for shutoff calculation in centrifugal pump.

Why we need such conservative rule (See attachment).

 

I mean "Suction design pressure" + 1.2 * Pump head

 

Why we should have pump "design pressure" condition during pump discharge blockage and head rise. 

 

Nothing attached...

[fallah]

As some general rule it is proposed to use following formula for shutoff calculation in centrifugal pump.

Why we need such conservative rule (See attachment).

 

I mean "Suction design pressure" + 1.2 * Pump head

 

Why we should have pump "design pressure" condition during pump discharge blockage and head rise. 

 

Because due to pump discharge blockage, it's feasible for the relevant suction drum to go to design pressure hence relevant PSV set pressure...

[Ghasem.Bashiri]

Such possibility is not applicable to options such as pump discharge of tower. 

[breizh]

Hi,

No attachment ! 

Go to More Reply options, bottom right button,,click on it and follow instruction to upload a document.

Without drawing itis impossible to get a meaningful answer.

BTW no context, just a "general "comment from you. 

Apply Bernoulli to get your answer.

Breizh

[snickster]

The design pressure of the discharge piping of a pump needs to be based on the maximum pressure possible which is the maximum suction pressure plus the shut off no flow dead head pressure.

 

During the design phase the actual pump to be eventually purchased is typically not know unless the pump is sole sourced beforehand.  If the actual pump to be used in the system is not knowned, then the dead head no-flow pressure of the pump can be estimated by 1.2 to 1.3 times the normal rated operating pressure based on the slope of the typical centrifugal pump curve.

Edited by snickster, 10 December 2023 - 06:25 PM.

[breizh]

Hi,

Probably good stuff for you and others to review, using this link underneath.

https://www.pumpfund...e.htm#download6

Breizh

Attached Files

•  sizing, specifying,selecting centrifugal pump.pdf   200.33KB   61 downloads

[fallah]

Such possibility is not applicable to options such as pump discharge of tower. 

 

Which characteristic(s) of the towers would lead to get such conclusion?