basic pipeline system question

[CarolinaPE]

I have a homework problem of sorts involving pumping seawater at 15,000 gpm and 3500 feet of head. Would it be best to have several pumping stations in series and go with a lower pressure class of piping, etc? Just ballpark estimate or recommendation would be ok for my purposes. Thanks.

 

[MiketheEngineer]

If its homework - its your job to work out the details!! We don't do that here.. Sorry

 

[BigInch]

Please tell me it's engineering job related. Site policy prohibits posting school homework.

Generally the fewer pump stations required, the better and the higher pressures and higher material strengths typically are more economical. That's the reason that there are higher pressures and higher material strengths on the market these days. Otherwise we'd still be using bamboo pipe.

If you can reduce your head by 150 feet, you're at the top of the ANSI#600 class ratings of 1460 psig (normal temperatures).

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[TD2K]

I'm interested what application needs that much seawater at that pressure. If it's an RO plant, it's the mother of all RO plants.

 

[BigInch]

I figure it's LNG regasification, or just a normal water supply project. Today... maybe emptying the NY subway.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[CarolinaPE]

Thank you BigInch, yes it is work related. I called it a homework problem "of sorts" because that is what it felt like. My background is mechanical building systems which usually use 125# or 250# systems and am not familiar with pipeline applications. I cannot really reduce the head as much of it is elevation. So it sounds like potentially two pumping stations and ANSI #600 class rating system would work. Thanks again.

 

[cloa]

It sort of buggers belief that engineer would think that a student would really have such a question (I never had anything like a real situation) or a student would ask for a ballpark answer for such a question.

 

[BigInch]

It's possible that you could do that head with one station using ANSI#900 only near the pump station, then ANSI#600 for the rest of the way, but you need to have a cooperating elevation profile. Do you know what the elevation profile looks like?

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[CarolinaPE]

Good point, unfortunately I do not know the exact profile but could find out. The pipe size is pretty large (48"), do you know of any manufacturers of piping in this pressure class and diameter? Being it is saltwater would a carbon steel pipe with an HDPE liner be the way to go?

 

[BigInch]

48" is no problem. Two pipelines in the UAE are now in operation, the Habshan-Fujairah Oil Pipeline having just started up this year, and Dolphin Gas from Qatar are both 48".

http://www.ipic.ae/en/projects/desc.aspx?proj_id=7

http://www.europipe.com/143-1-Dolphin-Energy--ADCOP.html

I think we have recently made a proposal for a similar diameter HDPE lined steel pipeline system for salt water in Iraq.

I doubt that you'd need more than 25 to 40 miles of high pressure line (over 1460 psig).


"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[CarolinaPE]

Thanks again, much appreciated.

 

[BigInch]

When you have more info on the profile, we'll have another look, OK.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek