Material for 10000 PPM Chlorides 2

[nickypaliwal]

Which material can be used for the piping and the pump for above chloride content. Chlorides of 10,000 PPM.

Operating Temp: 45 deg C.

Also recommend material for even higher chlorides say Sea Water.

 

[EdStainless]

At what pH? near neutral?

Cost wise the first choice would be non-metallic, either solid plastic or fiberglass.
That is if the temp and pressure allow it.

If you want to go metal you really are looking at alloys suitable for seawater service.
The Cl level is not the major factor, Temp and pH are more important.
Alloys such as 6% Mo superaustenitics (AL-6XN, 25-6Mo, 1925hMo), or for thin wall tubing a superferritic (Sea-Cure or AL-294C), or a superduplex (255, 2507) all have proven service in these conditions.

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Plymouth Tube

 

[nickypaliwal]

Thanks for your response ... Our client does not agree with Superduplex without any reference.. Is there any standard document available for the same... Also for the other suggestions of 6% Mo, can you please advise any document... NI-AL Bronze is Ok but we can not find suitable (approved) suppliers so is not an option...

 

[EdStainless]

There is a ton of data in NACE or North Sea specs about using these alloys.
The 6% Mo alloys have been in use in seawater for 30 years, they are considered legacy materials.
Look at the ATI reference

https://www.atimetals.com/products/Pages/al-6xn.aspx

I wouldn't touch NAB for piping (pumps and valves maybe, but it needs low velocity), maybe 70/30 Cu/Ni as another option, but much lower strength than SS and it has its own corrosion issues.

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Plymouth Tube

 

[moltenmetal]

Unless this is for extremely high pressures, why on earth wouldn't you use a non-metallic? I'd prefer corrosion immunity to corrosion resistance any day of the week.

 

[EdStainless]

At 45C and perhaps with chlorination non-metallics will not be free from long term environmental degradation.
But that said they would be my first choice also.
Unless heat transfer is involved (like in a heat exchanger) they are often a much more economical option.
One reason is that people often are reluctant to spend the money on the correct alloy so they try to cut the corrosion resistance close. This results in serious ongoing corrosion issues and high maintenance costs.

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Plymouth Tube

 

[nickypaliwal]

Although I don't remember the exact pressure but it was considerably high... I am not aware of flow rates limitation of NI-AL Bronze ... Can you please elaborate....

Also do you mean that DSS can be used for Sea Water application at temperatures of 45 deg C... Same is mentioned in NACE ??

Non metallic is not considered an option here ...

 

[racookpe1978]

Well, then don't guess at the pressure. Go get the exact pressure.

 

[EdStainless]

A superduplex would be considered a seawater service alloy, these are alloys with higher Cr and Mo than the standard 2205, it isn't a seawater grade.
If you really need strength then a a superduplex would have advantages.
But the welding of these alloys is much more difficult that for the superaustenitic alloys.

If you look in data from Outokumpu you can find temperature and Cl limits for duplex alloys.

http://tools.outokumpu.com/spt/corrosion/corrstart.asp?_ga=1.163791615.198702125.1416109504

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Plymouth Tube

 

[SJones]

Since the subject fluid is aerated, this link might be of use in negotiating with your client:

http://www.outokumpu.com/SiteCollectionDocuments/Outokumpu-corrosion-management-news-Acom-2-2014.pdf

Steve Jones
Corrosion Management Consultant

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

All answers are personal opinions only and are in no way connected with any employer.

 

[moltenmetal]

If the pressure is high and the temperature is not, then non-metallic lined construction is the way to go.