LIQUID LINE SIZING

[chimieindustrielle]

Hello friends

Im sizing liquid line , and I would ask if a pump suction line includes all lines and manifold before pump or a pump suction is just the last line before the pump ?

Thanks a lot !

Regards !

 

[EmmanuelTop]

All lines are included because pressure drop in pump suction is a critical item. There are no reasons to distinct between manifolds, common suction lines, and individual suction lines.
Some rules of thumb for sizing liquid lines:

http://www.eng-tips.com/viewthread.cfm?qid=391381

Dejan IVANOVIC
Process Engineer, MSChE

 

[georgeverghese]

If you are doing suction line pressure drop calcs for the purpose of getting a value for NPSHa, the term "suction line" starts at the location where the liquid last equilibrated with a vapor space - this would also mean the liquid residence time in this equipment is sufficient for the liquid to reach equilibrium with the vapor. If the liquid has flashed out some vapor in this vessel, the residence time and liquid level must also be adequate to minimise vapor phase carryunder into the pump suction line.