Seawater Intake Pumps

[jmas]

Does anybody knows why the designer of this intake, decided to have a above-ground discharge for seawater pumps, first, and then let them going U/G after some meters?
Let it asked in another way. If the outlet run U/G from the begining, then we have shorter pump, and therefore less material for it (cheaper pumps).
FYI i download the picture by googling.

 

[cvg]

see double post in the geotechnical forum

 

[vpl]

specifically, thread274-264580.



Patricia Lougheed

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[TenPenny]

Having a ug discharge won't change the amount of material in the pumps. The lenght of the pumps is determined by the depth of the intake and low water level.

If the discharge was ug, the meters would be ug, and would be at risk of flooding; also, the floor would have to have openings for access to the meters.

 

[jmas]

Thanks TenPenny for your reply. But, please consider that with fixed suction level we can have both A/G and U/G discharge. Considering expensive SS for pumps, less material saves a lot of money, that cover costs for civil works (openings for access?).
if take a look to the picture again it seems the piping is not CS. it resembles more to the HDPE (or GRP), which is weak in shear comparing to the CS. in this regard i think settlement of concrete intake is main reason to have A/G discharge to avoide direct shear in piping, and change it to tension and comopression at some meters away.
Am i right?

 

[vpl]

jmas,

Since this is a picture you Googled, how do you know the pumps are stainless steel?

When I first saw the picture, I thought it was a construction drawing for a plant I've been to in the US -- which really surprised me that the plant I'm thinking about would have construction drawings on the web.

Patricia Lougheed

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Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.

 

[rmw]

To answer your question, yes, I know why. Some parts of those pumps that are exposed above ground just aren't designed to be buried. The area around where the pump shaft goes through the stuffing box would just hate being surrounded by a bunch of dirt. (Sorry Civil brothers, soil.)

Not to say that if that was an important thing a pump couldn't be designed to be submerged in dirt, after some are designed to be submerged underwater.

But these pumps obviously weren't.

rmw

 

[TenPenny]

jams

You don't have to agree with me if you don't want to. There is no cost savings with UG discharge pumps.

 

[jmas]

To vpl: the link is

http://www.panoramio.com/photo/16091735

which is uploaded (as the link said) by Yeong Wei Kheen and related to Dung Quat Refinery : Unit 34, perhaps your plant moved to vietnam overnight?!
All of the pumps that i've seen and transfer seawater was made mainly from SS (i mean the parts in touch with seawater), what other material do you reckoning?
To rmw:
Please see my thread:

http://www.eng-tips.com/viewthread.cfm?qid=263587&page=1

To better understand what i mean.