[MW:23811] Re: FW: 23770] Weld corrosion testing on an ASME cladded pressure vessel. (UCL-32)

Hi Pradip,

Thank you for the corrosion guide with highlighted marks. 

Yes, TEG is not corrosive.

I think 316 SS cladding is to protect the contactor vessel against galvanic corrosion due to the 316 SS packing fitted inside.

Other TEG vessels (reboiler, flash tank, surge drum) and piping are made of CS and don't have cladding.

Our mechanical engineers confirms that there is no need corrosion tests.

The client confirmed the same.

Client's engineering company is Technip.

Only DNV raised this corosion requirement based on UCL-32.

This block all the approval process.

We don't want to entertain irrelevant requests it it is not justified.

This is an open door to other requests of same types that costs money and type.

We performed already a ferrite test on the weld coupon and it passed successfully.

I received many other replies confirming that the weld corrosion testing is not required i the client don't require it.

The weld filler is the same material as the cladding (316 SS) ; so, corrosion resistance o f both material are matching.

Than you again for your detailed reply.

2015-10-24 19:45 GMT+07:00 pgoswami <pgoswami@quickclic.net>:

Hi Duke,

 

TEG is not very corrosive, if you look at this data sheet (Watlow Corrosion Guide) the recommendation is that 316 S.S has a rating of "A-Good category " in TEG. Please note these data are for general information and further guidance. The

​​

onus of acceptability is primarily with the process design /mechanical design  personnel of the Engineering Consultant and client's engineers.

 

You need to validate the information with your design team.

 

At the same time it does not harm to carry out ASTM A 262 Practice –E, IGC test (the most common IGC test for austenitic stainless steels) on the plates or weld coupons. You may please discuss this issue with your AI. Most of the austenitic stainless steels if manufactured  and heat treated properly in the mill will invariably pass this test. However failure of this test may increase the potential to inspection hold ups.

 

Please check with the plate mill, on the chances of IGC practice E pass or fail criteria of the clad plates in case the AI insists the same. Same would be applicable for welding consumables also.

 

As for the statement below from UCL-32, it's a generic statement to safeguard against improper design. It's always a requirement in Corrosive media to match or overmatch the corrosion resistance of the base and weld metal to the process fluid involved. That's why all the ASTM-A-262 tests (Practice A,B, C, D,E) are insisted by the designers.

 

 

Thanks.

 

Pradip Goswami, P.Eng,IWE

Welding & Metallurgical Engineering Specialist

Hamilton, Ontario, Canada

pgoswami@quickclic.net

pradip.goswami@gmail.com

ca.linkedin.com/pub/pradip-goswami/5/985/299

 

 

---

From: Minh-Duc Pham [mailto:mdpham1@gmail.com]
Sent: Thursday, October 22, 2015 12:41 AM
To: pgoswami
Subject: Re: FW: 23770] Weld corrosion testing on an ASME cladded pressure vessel. (UCL-32)

 

Hi Pradip,

 

No weld corrosion testing is required in the project specifications and the client confirmed it.

 

Fluid is TEG (Triethylene Glyclol).

Design pressure/temp. : 42.2 barg/100 deg.C

Internal structured packing in 316SS

 

Cheers,

 

2015-10-22 10:42 GMT+07:00 pgoswami <pgoswami@quickclic.net>:

Hi Duke,

 

Did the project specifications or design documents called for weld corrosion testing  What's  the service media?? Appreciate if  you could  specify the design requirements.

 

Thanks.

 

 

Pradip Goswami, P.Eng,IWE

Welding & Metallurgical Engineering Specialist

Hamilton, Ontario, Canada

pgoswami@quickclic.net

pradip.goswami@gmail.com

ca.linkedin.com/pub/pradip-goswami/5/985/299

---

From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Duke
Sent: Wednesday, October 21, 2015 7:03 AM
To: Materials & Welding
Subject: [MW:23770] Weld corrosion testing on an ASME cladded pressure vessel. (UCL-32)

 

Hi all,

 

We have manufactured a glycol contactor vessel using carbon steel plate with 316SS internal cladding (3 mm).

 

DNV-GL, the vessel 3rd party inspector, is asking for a weld corrosion testing.

 

The project specification/data sheets does not request any weld corrosion testing.

 

DNV-GL interprets the UCL-32 (Weld Metal Composition) of ASME VIII div. 1 as a corrosion testing requirement.

 

UCL-32 states the following :

Welds that are exposed to the corrosive action of the contents of the vessel should have a resistance to corrosion that is not substantially less than that of the corrosion resistant integral or weld metal overlay cladding or lining. The use of filler metal that will deposit weld metal with practically the same composition as the material joined is recommended. Weld metal of different composition may be used provided it has better mechanical properties in the opinion of the manufacturer, and the user is satisfied that its resistance to corrosion is satisfactory for the intended service. The columbium content of columbium-stabilized austenitic stainless steel weld metal shall not exceed 1.00%, except when a higher columbium content is permitted in the material being welded.

 

As you see, there is no mention of any corrosion test requirement in this article and the client confirmed that he does not require any weld corrosion testing.

In the same meeting, DNV-GL confirmed that he will not accept the contactor vessel.

 

I would like to have your interpretation and experience regarding weld corrosion testing of cladded ASME vessels.

 

Thank you.

 

--
You received this message because you are subscribed to the Google Groups "Materials & Welding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to materials-welding+unsubscribe@googlegroups.com.
To post to this group, send email to materials-welding@googlegroups.com.
Visit this group at http://groups.google.com/group/materials-welding.
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/942a0fd4-5d17-4f7a-941b-6d92055003aa%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

 

--
You received this message because you are subscribed to the Google Groups "Materials & Welding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to materials-welding+unsubscribe@googlegroups.com.
To post to this group, send email to materials-welding@googlegroups.com.
Visit this group at http://groups.google.com/group/materials-welding.
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/CABsoWs0tiT71_jLLCDwB_Tsy%3DYDOnB2sHbSD4f7KWHPasykuig%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.