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Hardness test requirement 1

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johnthebest

Mechanical
Mar 7, 2018
57
Hello everyone
I would like to have your help about this technical query

In our project specification, we said the following:
when required, hardness test shall be performed on.... "see page 3 of 3 in the attached file"

The contractor is proposing the following:
For P1 material weld and HAZ with PWHT hardness values shall be 200 BHN max.
For P1 material weld and HAZ without PWHT hardness values shall be 237 BHN max.

and the justification is given in page 1&2 of the attached file

Now what I want to understand: what does it mean "when required" in the spec and is there any deviations from what the contractor is proposing.

Thx in advance
 
 https://files.engineering.com/getfile.aspx?folder=450af870-0556-4836-bd09-8841eb666c8d&file=1234567.pdf
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So,let me get this straight.
You as the client have a project spec.
The contractor wants to do something differently.
You want us to tell you what to do with the contractors proposal ?
Don't hold your breath !
 
Actually the spec was made by a third party. what I want is to an interpretation from a contractual point of view.
 
You are missing the point.
Whoever wrote the spec is irrelevant.
You, as the client own that spec as you, the client accepted that spec.
If you are not knowledgeable / experienced enough to be able to resolve this then give it to someone in your organisation who is.
 
"When required" will be dictated by the specification itself, probably by way of referencing an external standard. Looking at the hardness numbers in the specification, and in the counter proposal, that external standard appears to be NACE MR0103/ISO 17945, although by poor specification writing, the 'third party' may well have introduced NACE MR0175/ISO 15156. A review of these standards would tend to suggest that the contractor's counter proposal is not that unreasonable.

Paragraph 5 of the contractor's justification is technically incorrect with respect to a threshold H2S partial pressure.

Steve Jones
Corrosion Management Consultant


All answers are personal opinions only and are in no way connected with any employer.
 
"When required" could also be stated on specific engineering parts drawings.
 
@SJones
From what I understood, there is a deviation made by the contractor regarding the spec clause.
 
I just got a reply from the contractor that the partial pressure of H2S is too low that leads to NACE is not applicable. Plus his understanding is that when required means if it is required by the process or the code. so this clause limitation is not a must to do.
 
It is assumed that your design engineering firm wrote the specification. Ask them to clarify what they meant. Also Steve is correct; the purchaser/end user governs requirements concerning corrosion issues.
 
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