Corrosion Inhibitors for Open Loop Sea Water Cooling Process 1

[TomosSmith]

Hello,

We are having some corrosion issues with Duplex stainless steel grade 2205 piping used in the Gulf region for a sea water cooling process. We are yet to find the root cause of the corrosion and are presently investigating if it is a welding problem, or a problem with the material selection generally.

We have reference of other projects in the area using corrosion inhibitor dosing at the sea water inlet.

Does anyone have any experience to share of duplex 2205 corrosion in Gulf seawater, and use of corrosion inhibitors?

Thanks,
Tom

 

[rmw]

Gulf of.....?

And on land, near shore, off shore?

rmw

 

[TomosSmith]

Arabian Gulf seawater, and it's a near shore installation (on reclaimed land).

Tom

 

[arunmrao]

Exova has a good corrosion control lab in the region. You may contact them for help.

_____________________________________
"It's better to die standing than live your whole life on the knees" by Peter Mayle in his book A Good Year

 

[SJones]

2205 is not the correct choice for seawater of that temperature. A superduplex (of minimum PREN 40) would also be a marginal choice since the temperature will get above 30 deg C. If you want to keep the stainless piping, try Googling 'resistor controlled cathodic protection'. Failing that, start again and use GRP. Good luck.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[TomosSmith]

Steve Jones - thanks.

 

[winflex]

2507 Super Duplex will be required at these temperatures.

 

[SJones]

Super duplex will still not be sufficiently resistant.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[MJCronin]

I would like to add the fact that not all seawater is the same.

While the material choice of 2205 duplex is poor for the Arabian Gulf seawater, (high salinity, high temperature) it is a reasonable choice for castings used in the Baltic (near Sweden... look it up !)where both the salinity and temperature levels are more modest.

The minimum PREn of 40 for seawater, although most often reasonable, is not an iron-clad rule. Other factors come into play.

 

[jwray76]

How about sea water with 24 ppt salt content and temperature of 80 deg. F? We have an application in Trinidad with these water conditions. Looking specifically at a 48 inch tubular casing for seawater intake pumps. These will be extremely costly in a high PREN material. We have the option for fiberglass and I am currently evaluating that option as well.