Material selection cooling hot produced water 1

[olfar]

I'm asking for advice regarding material selection for a plate heat exchanger that shall be cooling hot produced water, maximum temperature of 130 degree C, by ambient seawater. The produced water contains max 180 000 mg/l with chlorides and shall be free from oxygen. Seawater inlet temperature is 20-25 degree C and max 70 degree C at the outlet. Connecting piping will be GRP or lined carbon steel at seawater side and Type 22 Cr duplex at produced water side.
Is Titanium Grade 1 or 2 suitable?
Is any cupronickel alloy suitable?

 

[EdStainless]

I believe that any Cu/Ni will handle that service.
Considering all, Ti looks like the only viable option.

= = = = = = = = = = = = = = = = = = = =
Still trying to help you stop corrosion.
formerly Trent Tube, now Plymouth Tube
eblessman@plymouth.com
or edstainless@earthlink.net

 

[TVP]

As EdStainless already stated, Titanium Grade 1 or 2 is suitable for this type of service. I would investigate this option instead of Cu/Ni alloys.

 

[SJones]

The above answers sort your HEX materials out, but what about the piping? Stick with GRP for the seawater, it will be a lower life cycle cost than lined carbon steel. For the produced water system, take a look at UK Health & Safety Executive Offshore Information Sheet No 07/2007

http://www.hse.gov.uk/offshore/infosheets/is7-2007.pdf

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[olfar]

Thanks to you all for good answers.
I agree that Titanium Grade 2 is suitable for the seawater side, however, are there any risk for crevice corroison at the produced water side? Max temperature for Grade 1 and 2 is 80 deg C in salt solutions according to Titanium Technical Data Sheets. Any comments?
Information Sheet No 7/2007 supports that traces of oxygen is possible in produced water systems and that 22Cr duplex suffer from SCC initated from both inside and outside. Is the lean duplex Grade AL2003 a better selection than 22Cr for the produced water piping?
Any experience with AL2003 for hot produced water enviroNments?

 

[EdStainless]

No, 2205 will have better crevice corrosion resistance than AL2003. Make sure that if you go that way you specify S32205, not S31803. Also require A923 corrosion testing on all of the pipe.
Think seriously about outside coatings.
The superduplex alloys have not shown to have better CSCC resistance in lab testing.

= = = = = = = = = = = = = = = = = = = =
Still trying to help you stop corrosion.
formerly Trent Tube, now Plymouth Tube
eblessman@plymouth.com
or edstainless@earthlink.net

 

[TVP]

olfar,

The susceptibility to crevice corrosion for CP Ti depends on the pH in addition to the temperature. If the pH is greater than ~ 8 then CP Ti Grade 2 is acceptable. CP Ti Grade 12 can be used at temperatures exceeding 250 C at pH greater than ~ 3.