Impact Test SA-182-F51 Flanges 1

[AarVee]

My supplier is designing a vessel with duplex flanges for -45degC under ASME VIII-1. Per UHA-51, these SA-182-F51 flanges must be impact tested.

What sort of documentation should I expect from the supplier to prove that these forged flanges are properly tested?
Are sample flanges selected from each batch and destructively tested?
Is there a supplemental Spec that should be cited in the MTR?

Feel free to direct me to an appropriate, existing thread...my own searches came up empty.

Thanks.

 

[XL83NL]

My first guess would be to refer to supplemental requirements of A/SA182 for Gr. F51, but I think there's nothing in there w/ respect to nothc toughness.

Im sure others may provide you better help, but my 2nd hunch would be (based on experience with these flanges for piping @ -30 deg C) to require minimum notch toughness values on the MTR (which may also be an EN 10204 3.1 cert.).
Another way would be to check if any of the ASTM A923 methods (I think more specifically method B, which calls for

11.2 An impact test for the purpose of detecting intermetallic phases shall consist of a single specimen taken from the product piece or lot to be represented.

can help you 'out', i.e. assure if the test results meet the Code requirement.

Notch toughness tests are made on a destructive test base, on a sample basis from each lot.
Ive noticed most F51 flanges by standard have one of the three A923 tests on their 3.1 cert. (esp. when dealing with more reputable West-Eur suppliers), so with a bit of luck you may find a few flanges on stock that have all the Code requirements.

 

[SJones]

The documentation you should expect is the documentation that has been specified. Likewise, any supplementary specifications. A number of users ask for the API TR 938-C Charpy requirements of 70J average at -46 deg C. NACE Corrosion 2012, Paper C2012-0001096 gives a good discussion on the background to this.

What are you doing about corrosion testing?

As to what sample material is specifically tested that is governed by SA-182 and SA-961

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.

 

[XL83NL]

Well put Steve.
Do you happen to know if that NACE paper C2012-0001096 is directly available throughe NACE's website, or do I need to purchase it through corrosionanalysisnetwork.org?

 

[AarVee]

Thanks all, my understanding of the issues considered under ASME VIII-1 is becoming clearer:

The MTR for the duplex flanges should include documentation that testing has been performed to minus45degC per UHA-51(a)/UG-84(e)(2) on three specimens from each lot of (20) parts. Testing is to be performed per SA-350, using the acceptance criteria of Tables 5 & 6. It is up to my supplier to procure the material with this certification from his vendor.

Furthermore, the supplier must perform impact tests on welded specimens. I interpret this requirement as being covered by an appropriate PQR.

Regarding corrosion, my company requires only ferrite testing in the PQR and spot-checking the production welds for this grade of duplex. (For super duplex, we would have required a salt-spray test.)

What have I overlooked?

 

[XL83NL]

For more assurance on corrosion resistance, you may call for one of the methods of ASTM A923 to be on the MTR (i.e. you have to specify this too in your PO).
Im sure Steve can back me up or have a better answer, but that's what I would do.

Additionally, but im not 100% sure on this one, you can also look into AP TR 938-C for methods on 'covering' corrosion protection in your PQR.

 

[SJones]

@XL83NL:

http://www.nace.org/cstm/Store/Product.aspx?id=81666019-82ed-e111-ac69-0050569a007e

@AarVee:

Sadly, it appears that you have overlooked years of experience with poor supply of duplex stainless steel. It is recommended that you study API TR 938-C and, if you can get hold of it, EEMUA 218. It simply can't be left to just specifying a standard and a grade and hoping that everything is OK. Dealing with duplex stainless steel is an involved process that can have very unsatisfactory outcomes if time and resources are not devoted to quality assurance starting with supplier selection:

http://www.standard.no/en/Sectors/Petroleum/NORSOK-Standard-Categories/M-Material/M-6503/

If you wish to have an idea of supplementary requirements that might have been specified take a look at datasheet MDS D44 in this document:

http://www.standard.no/en/Sectors/Petroleum/NORSOK-Standard-Categories/M-Material/M-6304/

to which should be added a 24 hour ASTM G48 test at room temperature with the acceptance criteria of no pitting and weight loss less than 4 grammes per square metre. The Charpy energy acceptance criteria issue has already been discussed above.





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.

 

[SnTMan]

I hate the damn stuff, everybody seems to think its less expensive than 304, which, based on as-fabricated cost, I find hard to believe.

Spent $1500 ea. for three 1" SR weldells a year or two ago. Spent $40 ea. for 5/16 x 1 1/2" machine bolts. A hundred or so of them.

Get real.

Regards,

Mike

 

[AarVee]

Thanks again for sharing your thoughts and experience. It has been very helpful.