Turbo-pump charge & discharge line size

[pouria77]

the pump suction line is usually one size greater than discharge line in order to NPSH and fluid velocity problems. I see a turbo-pump with power of 12000 hp for crude oil pipeline which have same suction & discharge line size.
have any reason foe equality of suction & discharge line size of this turbo-pump?

 

[Artisi]

Yes, because that's the way it was designed as being sufficient for the inlet flow.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[LittleInch]

That's a pretty big pump. At that sort of size the pump normally wants at least 2 or 3 bar suction and if you look closely it is probably about 5 or 6 bar. That is provided by a booster pump upstream and hence pipe size is not determined by NPSH in the same way as other smaller pumps, but, as artisi says, designed that way to cope with flow.

Just a guess, but if you give more info you might get more feedback.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[Artisi]

I think that a company who can design a 1200hp pump can be given the benefit of the doubt that they probably know what they are doing regarding the sizing of the inlet branch.
Wouldn't you agree?

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[LittleInch]

Very much so.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way