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Internal Pipe Corrosion from Seawater

Internal Pipe Corrosion from Seawater

Internal Pipe Corrosion from Seawater

(OP)
I am designing a piping system in which untreated seawater is pumped through the lines. I have done some research, and I have found many options. I am wondering if anyone can make a recommendation for my situation and narrow my search.

Stainless steel and other expensive metals are not suitable for this operation due to cost.

PVC and other plastic pipe are also not suitable.

I have been researching seawater resistent epoxy internal coatings. Does anyone have any experience with this?

The life of the pipe should only be 5-10 years.

Thanks

RE: Internal Pipe Corrosion from Seawater

What diameter of line and how long of a run?
For large lines cement lined steel is common, or simply reinforced concrete.
Resin lined steel is often used also.
For such a short service life SS is too expensive, and most other options will be also.  Typical design life is 40 year min with expectations of 75 years.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

RE: Internal Pipe Corrosion from Seawater

What fluid speed?  (This will affect erosion rates on the pipe liner.)

Have you evaluated (by spreadsheet of initial cost of purchase of pipes plus supports plus valves plus lining price compared to final price of larger pipes plus larger supports (but fewer supports?) plus liner price plus larger valve prices plus ijncrease (?) installation and shipping prices) to see what happens if you increase pipe sizes by +1 size (from 12 inch to 14 inch dia, or from 16 inch dia to 20 inch dia) to slow flow rate and reduce erosion levels?   

 

RE: Internal Pipe Corrosion from Seawater

I believe that the traditional copper-nickel pipe is the best for untreated sea water. It is the only one to resist biological growth fouling the pipe and has good corrosion resistance. Please note that the sea water piping on every offshore platform and O&G facility is using the Cu-Ni pipe or PVC pipe.
Cheers,
gr2vessels

RE: Internal Pipe Corrosion from Seawater

You might look into HDPE material depending on your temp/press.

 

RE: Internal Pipe Corrosion from Seawater

apark19,

Shipboard water desalination systems have ductile iron piping as entry level material of construction, while nuclear submarine water desalination systems use titanium - a wide extreme indeed.

The older power plants at coastal locations had ductile / cast iron used for seawater cooling systems.  Coastal cities fire sea water piping and hydrants also have ductile iron piping.  

RE: Internal Pipe Corrosion from Seawater

Cement lined carbon steel has been used for decades in sea water, firewater systems.

RE: Internal Pipe Corrosion from Seawater

apark....

Reconsider FRP/GRP piping materials. Stay away from metallics

They are suitable for a long life, have virtually no seawater corrosion and they are permitted by the USNAVY fir shipboard use.

What was your reason for omitting this important group of materials ?

(I agree that HDPE and PVC are not suitable....and they lack strength)

   

RE: Internal Pipe Corrosion from Seawater

How about P110 lined GRE lining?

 

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