Hi Vino,
MR0175/ISO 15156-2:2009, clause 7.3.3 specifies very clearly:-
- Processes and consumables should be selected in accordance with good practice and to achieve the required cracking resistance..
For example in sour service :-
- Base materials needs to meet MR. 0175 specification.The mills have to certify this either through SSC testing or by the rules of MR 0715, which they do generally.Without any certification from the mill one would not proceed for the acceptance and further activities e.g fabrication.
- Qualified welding procedures have to meet the sour service hardness requirements (22 HRC)
- If the above requirements are met, then by default also the welding consumables should meet MR-0175 acceptance criteria , as a good engineering practice. Welding consumables can not be a missing link for sour service environments.
For manufacturing any welding electrode, e.g , E-7018-1, the respective batches, lots have to meet AWS SFA 5.1,requirements. Sour service requirement should require some "authentication or statement or reconciliation on the part of the manufacturer". That's, because sour service requirements are additional to the requirements of AWS.Many electrode manufacturers may not do the this without additional testing/documentation charges. The certification route to meet sour service requirements are not very different than what's followed for conventional consumable testing. NACE does not dictate this certification process, in many instances it's as decided by the purchaser and the industry specifications.
-
Quote- Clause 1.0-Scope:- It (MR-0175) supplements, but does not replace, the materials requirements of the appropriate design codes, standards or regulations.
In your case purchasing specification does not include " certification" as a mandatory requirement, thus the consumable supplier is reluctant to do so. Should fabrication of equipments for sour service applications be a regular feature, then I would advice to incorporate this requirement as a part of your specification in future. This may involve a few extra dollars, but could give you good peace of mind.
In the present context as there's no help from the supplier, it would be prudent to verify the MRT of the procured electrodes and get the acceptance from the client and ensure that only the accepted batch or batches getting used for welding.
Thanks.
Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist & Consultant
Ontario,Canada.
Email-pgoswami@sympatico.ca,
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Vino Varghese
Sent: Wednesday, October 12, 2011 2:22 PM
To: materials-welding@googlegroups.com
Subject: [MW:12663] Sour Service / Any special requirement for Welding Consumable to be considered!
Dear All,
I would like to know whether we require any special requirement to be met for Consumable under NACE Requirement except for the "Ni" content and Hardness? Do we have to consider the "S" content as NACE refers to limit sulphur for base material?
Base Material - SA 516 Gr 70 N
Construction Code - ASME Sec VIII Div 1
Service - Sour
Additional Standard to be followed for the Project - NACE MR 0175
We have recieved material consumable 7018-1 and MTC reflects a 3.1 Certification and meets all the requirment of ASME Sec II Part C but the Consumable Certificate do not declare "NACE Conformity to MR 0175", although hardness value is provided.
Do we really require a NACE Confirmation for the weld consumable? If so, please support with Code/Standard.
If any additional requirement to be carried in accordance to NACE, please provide list of test required to qualify the Weld Consumable in accordance to Sour Service requirement. Moreover, the Project document do not reveal any special requirement for the weld consumable and we have contacted the Manufacturer(a leader) which decline to provide NACE confirmation.
Hope to see all opinions/guidlines for the above query and I am sure Mr. Goswami has a edge to my query.
Thanks & Regards
Vino
Doha, Qatar
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