Sea Water Service Pipeline, 316L?
Sea Water Service Pipeline, 316L?
(OP)
I am a mechanical engineer at a large petrocehemical complex in Turkey. We are located on the seaside and we have decided to feed our fire water pipeline with sea water during an emergency such as lack of fresh water or very low fresh water pressure. In the project the suction line from sea to the main collector (serving three centrifugal pumps) is about 50m long. What kind of material is appropriate for the suction line? It will be full of sea water at all times. Is 316L OK? We do not want to have corrosion problem in the near future.





RE: Sea Water Service Pipeline, 316L?
With 316L, my first question would be wrt stress corrosion cracking due to the chlorides in sea water.
RE: Sea Water Service Pipeline, 316L?
RE: Sea Water Service Pipeline, 316L?
I have installed many systems for use on sea water, sewage sludge, potable water etc.
No fear of stress corrosion cracking
Standards are available from www.standards.com.au. Look for AS 3518 & AS 3690. Check out the drafts as AS 3518 is under revision and you may be able to download for free.
RE: Sea Water Service Pipeline, 316L?
CS pipe EFW cement lined, coated and wrapped to awwa spec. downside is the maintenance. if the mortar lining comes loose then you will start seing and repairing leaks. at the valve-to-pipe joint, you will also expreince some flaking of the mortar lining requiring another repair/replacement. note that once you losse the cement lining its an uphill battle to just keep on monitoring the line and fixing it. OK in your case since lenght is only 50 m.
between 4-36 NPS we have started using CS pipe lined with fiberglass (glass flake such as those made by Jotun) reinforced vinyl ester resin. for the small branch connection, we have selected B43 brass annealed (too small to lined properly). so far the result is better thatn the cement lined cs pipe.
fiberglass. we have consider it (lcc is really very attractive) but decided againts it. reason - if it breaks, reparing the line is a struggle especially in a very tight area (ive been into one inside the valve pit wiht sea water ozzing out like a fountain).
ss pipe. some says that scc is a concern. well for scc to occur three things must be present - residual stress, excessive amount of chloride (well for seawater of course it must be excessive)and temperature (most of the documented failure related to scc has these properties). mode of failure is leak. there is no weld repair. either you shutdwon the system to repalce your spool or you install a clamp and assess the risk. beside its costly.
RE: Sea Water Service Pipeline, 316L?
RE: Sea Water Service Pipeline, 316L?
RE: Sea Water Service Pipeline, 316L?
Some (10 or more) years ago Cunifer piping (=Cupro-Nickel) was the standard material for seawater, but nobody uses this anymore due to fabrication, installation and mechanical strength problems I think.
GRP is also used for seawater but normally only for "non-critical" systems, i.e. systems that is not required to work in case of emergency.
Maybe though for a large diameter onshore header it it is acceptable, and cheaper to use one of the other suggestions above.
Try the site www.steel.sandvik.com/
or www.avestasheffield.com/steel_grades.asp
They have specs for SMO254
regards
Mogens
RE: Sea Water Service Pipeline, 316L?
RE: Sea Water Service Pipeline, 316L?
most common for seawater are ,,,FRP'S or C.S.cement lined
FRP'S potential problems are breakage...
cement lined c.s problems are when lining is gone...
a decision i beleive should be based on how good u will design and engineer any of the two options...
316 L ( known limit for the clorides part is 50 ppm ) ? seawater (thousands of chlorides ) ppms ?! no way !
cheers
RE: Sea Water Service Pipeline, 316L?
For more responses to the same question, please see the following forum.
Materials Engineers Area - Corrosion engineering Forum
RE: Sea Water Service Pipeline, 316L?
RE: Sea Water Service Pipeline, 316L?
RE: Sea Water Service Pipeline, 316L?
RE: Sea Water Service Pipeline, 316L?
RE: Sea Water Service Pipeline, 316L?
That is really an important issue if you are taking the water directly from the sea, lake etc. It is apparent that there will be clams and other settlements at the pipe intake. We think about using a self cleaning filter at the pipe intake. Lakos has such a filter up to 460m3/h for sea, lake and spring suctions. One idea was to keep the pipe out of the water at idle times with some kind of lever system which may not sound very practical..At the moment we do not have a clear solution. I will appreciate any idea on this matter..
RE: Sea Water Service Pipeline, 316L?
RE: Sea Water Service Pipeline, 316L?
Just for your reference, In our power plant practise, we use GRP pipe for seawater intake DN2500 (undersea & underground). For aboveground, we use A53-B with rubberlinned. Rubber linning is an good option for seawater.
Regards
Kent
RE: Sea Water Service Pipeline, 316L?
Thanks
SA
RE: Sea Water Service Pipeline, 316L?
RE: Sea Water Service Pipeline, 316L?
Consider polypropalene. Sea life does not grow on poly. This would solve the clam problem. Also it high density poly is strong and would not be easily damaged.
Cement pipe using type V cement is very good for sea water but it is good at growing sea life such as clams, etc. If this is use it could be treated with chlorine. A chlorine solution can be derived from sea water with electrolysis. After about 8 hours it reverts back to sea water with no long term effects. Injection of this chlorine solution in the intake would keep sea life out.
Hope some of these suggestions help!
RE: Sea Water Service Pipeline, 316L?
RE: Sea Water Service Pipeline, 316L?
RE: Sea Water Service Pipeline, 316L?
I have a write up which i preapared for a seawater using chemical manufacturing company indicating the host of materials suitable for the service ant their priorities in selection due to varied reasons. i may share it if one wishes. No hold from my side. This can be emailed as MS Word doc file.
Narendra K. Roy
Gramya Research Analysis Institute,
PO box 4016, Vadodara 390015, India
Website: www.gramya.com ; www.charismaglobal.com