Duplex Stainless - ASME Pressure Vessels ? 1

[MJCronin]

A client has asked us about a vertical ASME Coded pressure vessel as part of a new project.

The material is to be duplex Stainless steel type 2205

Does anyone have any experience/recommendations/suggestions with regard to the construction of pressure vessels from this material ?

Thank you in advance

-MJC

 

[metengr]

MJC;
Go to this web site and download the publication at the bottom of the page, "Practical Guidelines for the Fabrication of Duplex Stainless Steels,

http://www.imoa.info/moly_uses/moly_grade_stainless_steels/duplex_stainless_steel.html

 

[SnTMan]

MJCronin, at my previous employer we built several S&T exchangers that were either completely 2205, or one side was, I don't recall which. Welding apparently was not big deal, I'll leave that to others.

Some Code considerations: You will probably have to impact test, duplex cannot be easily exempted as can austenitic. See, for example, UHA-51(d)(3).

Design temperatures are limited to 600 F. per Sec II, Part D.

ASME B16.5 flanges are listed for 2205, I don't recall if they are readily available or not, same with some other standard parts.

Overall these jobs were pretty straightforward.

Regards,

Mike

 

[dig1]

MJCronin,

Metenger and SnTMan have great suggestions and comments. The publication that Metenger references is a must read.

Impact testing can be a big deal, especially on flanges. My recent experience is that SA182-F51 flanges are available but often not impact tested and if it is necessary for you to have these impact tested then this quickly leads to additional expense. Same with SA790 for pipe (nozzle necks) (it is available but often not impact tested).

Because 2205 has a higher yield than both 300 series austenitics and SA516 Gr. 70 c/s the forming effort will be higher. It may not be an issue in your case but if you have a thick vessel with a small radius (all relative of course) this will have to be taken into consideration.

Many companies have specifications for duplex fabrication and often include ASTM A923 methods A, B, and C (some companies do not allow method A sceening to eliminate methods B & C). The method B impact test is done at -40C so if your customer is requiring this make sure that your plate supplier is aware. Not all plate, especially that from Europe, has ASTM A923 testing. As a side note, i have found that much of the duplex from Euroe does not have lateral expansion values from impact testing. make sure that you ask for these otherwise you will need to re-test yourself. I have been caught in that situation before.

Make sure you review any customer supplied specs. As I mentioned earlier, different companies have different requirements, which appear, at least to some extent, to vary by industry (in pulp and paper for example several companies have their own specs and expect them to be strictly adhered to).

One area which can be a problem is welding thin pieces to thick pieces (tubes to tube sheet for example). The thick piece acts as a heat sink and can cause a quench which may produce an undesirable phase balance.

I hope this helps some.

BR,

Patrick

 

[curlyjackme]

I just designed one that is being constructed now, and the company I work for has done many (also some duplex tanks). All of the above is great information so I will look at the welding aspect of the 2205 duplex. Make sure the welders test on the material to be welded. It does weld different than normal stainless material. Flux core welding is the way I recommend, and make sure every pass is ground clean. Duplex leaves a slag that is almost clear, make sure every pass is clean to keep from having any weld rejects.

 

[MJCronin]

Anybody else have experience with duplex pressure vessels ?

 

[boilerone]

I designed before vertical ASME code vessels with duplex SS materials but what is your detailed question after already having the valuable replies above?

 

[weldtek]

We've built a dozen or so over the past couple of years. Customer specs can have a great impact on the job, so, review them thoroughly. In addition to Code requirements, most specs call for certain chemistry restrictions, impacts ( even if exempted by UHA 51), hardness surveys, corrosion tests, and ferrite tests by the manual point count method. Plate manufacturers like Outo Kumpu are very familiar with these requirements and have standard products that meet most customer specs I've seen. Welding procedures and production tests can be very expensive depending on the extent of testing required by the specs.
As far as welding using the conventional methods, I don't think you'll have any problems, with the possible exception of the SMAW method which in my experience tends to yield ferrite on the low side of most customer requirements. Oh, make sure you deal with a reputable test lab, 'cause they're not all equal.

 

[MJCronin]

Weldtek

Can you recommend some vessel fabricators with experience ?

Thank you and best regards

 

[weldtek]

In what area?

 

[MJCronin]

Ohio/Illinois/ -- Central USA ?

I am having trouble finding fabricators who have experience designing/fabricating/inspecting/testing ASME Section VIII pressure vessels made from duplex stainless steel.

The vessels I am interested in are 12' diameter, 20 ft high, vertical axis rated at 125psig MAWP.....

Whom have you dealt with in the past ???

 

[dig1]

MJCronin,

I would recommend Miller Mechanical

http://www.millermech.com/,

Tate Metal Works

http://www.tatemetalworks.com/,

and American Tank & Vessel

http://www.at-v.com/.

I know that these companies are not in your area but these should be shop fabricated tanks and I have worked with each of these companies on duplex tanks which they have shipped to locations in both North and South America and they have done excellent work.

Patrick

 

[vesselfab]

you might try offehauser in Houston

http://www.offenhauser.com/

I think they could jump right on it

 

[gr2vessels]

Perhaps you should go overseas, a lot higher expertise, lower costs and delivery..you'll be surprised. Australia, India, but also France, Italy. U-stamp included.
gr2vessels

 

[vesselfab]

YEAH

but travel expenses for inspectors is hell

prefab meeting, in process, final, hyro

 

[dig1]

If you plan too look outside of the US, I would also suggest Arjay in Canada

http://www.arjayindustries.com/

and Terastorni

http://www.terastorni.com/eng/products.html

(TT may no longer hold a U stamp because most of the projects I have recently worked with them on are EN 13445) and Hollming Works

http://www.kkpaja.com/index.php?page=99

in Finland.

I don't believe it is fair to say that shops outside of the US have substantially greater expertise than shops in the US with duplex just as the converse is also not true. There are great shops all over the world which can do this work.

Vesselfab brings up a great point. Travel expenses are high then there is ocean frieght cost and logistics, customs, currency exchanges/hedges, making sure that the wind and seismic codes are applied correctly (just because they are in PVElite or Compress doesn't mean that the user understands (this can happen in the US too but is way off-topic)). These points are valid no matter where in the world the project is located (ex. importing into NSW Austraila from the US has certain complications). If you look overseas, which is a good idea, just make sure you have the complete cost/schedule picture.

Patrick

 

[AllHandlesTaken]

I have dealt with Ellett Industries in British Columbia quite a bit:

http://www.ellett.bc.ca/

And have found they produce very high quality products.

 

[davefitz]

some errors we encountered in the past:

- for wet FGD scrubber absorber trays, the thin wall welded supports failed at the weld interface due to fluid induced vibration,hgih stress raiser, brittle weld ( did not preheat- supposedly the only allowable case for mild preheat is when welding thin wall parts).


- same service, wallpapering or welding 2205 to CS , incorrect weld filler was used- supposed to over-match and use incolnel for such a DMW.

 

[weldtek]

The situations dave mentions sound like design issues as opposed to fabrication issues. As with most things, there's no panacea. We've used type 309Mo for certain carbon to duplex joints with no adverse effects. The right choice for any particular application may not be correct for another.
Preheat is not generally advisable, other than for the purpose of removing surface moisture. Even then, one must be careful.
Arguably, heat input and the related cooling rates are the single most important variable when welding duplex stainless steels. For good reason, most owners specify that PQR's be qualified on material thicknesses closely representing those to be welded in production. In some cases, we've had to qualify four PQR's to weld production thicknesses ranging from 3/16" through 1".
Heat input is crucial.