production weld test plate

[johnthebest]

Hello everyone. I am not specialized in the Boiler and Pressure Vessel engineering and I want your opinions about this clarification we got from the contractor.

In our specification of pressure vessels we said:

A production weld test plate is required for each weld procedure (WPS and WPQR) employed in the
fabrication of the longitudinal and circumferential seams.

Longitudinal Seams
Test plates for longitudinal seams should, wherever practicable be attached to the shell plate at one
end of the seam so that the edges to be welded are a combination and duplication of the corresponding
edges of the vessel seam.

Circumferential Seams
Test plates for circumferential seams may be welded separately from the vessel providing the technique used in their preparation duplicates, as far as possible, the procedure used in the welding of the appropriate seam of the vessel.

Now here is the clarification from the contractor:

(As per clause (production test plates), the contractor understanding is as below;

1. Longitudinal and Circumferential weld seams shall be interpreted as category A and category B joints respectively as defined in ASME SECTION VIII Div.1.

2. Production weld test plate is required for each weld procedure for welding of category A and B joints only when impact test is required.

CA to confirm / clarify above points.

After doing some research, I was not convinced about their understanding. what are your thoughts?

 

[SnTMan]

Well, without going into the Book, I'd say the contractors' understanding of what is required by Code is correct. Contractors' understanding of what is required by contract is mistaken.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[DVWE]

Agree with SnTMan. Not required by code, but if specified by your contract, they are bound to it.

The devil is in the details; she also wears prada.

 

Concur with SnTMan.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[david339933]

What is the MDMT....and what do you expect to accomplish with production test plates?

 

[johnthebest]

Thx for ur replies. So from what I understood of the specification is the following:
1. Longitudinal and Circumferential weld seams shall cover all the 4 categories (A,B,C,D)
2.Production weld test plate is required for each weld procedure for welding of all categories without the need of impact test criteria.

Am I right?

 

[CWEng]

I generally agree with the responses, but if impact tests aren't required, what is going to be tested on the production test plate? Section VIII spells out what to test, does your specification? If the testing was not specified, they could just weld the test plate(s) and then ship it with the vessel?

 

[johnthebest]

@CWEng
Testing of plates shall be in accordance with the code.

 

[david339933]

Again...What is the MDMT....and what do you expect to accomplish with production test plates?
The lack of knowledge, leads me to think this was carried over from a spec that required production impact testing, and now it's only about saving face....

 

[DekDee]

Agree with SNTMans original comments but we still need to take a step back.
Has the contractor built vessels without the production test plates and is now looking for an out ?
Or, (and this seems more likely based on OP) have they requested clarification prior to commencement of fabrication.
Asking for clarification on something over and above code requirements shows due diligence has been performed on the project specification.
I have spent the past 20 years reviewing project specifications (as both Client & Contractor Rep) and the majority of them are a joke.
Professional contractors will have competent people from the relevant fields reviewing the project specifications and asking the pertinent questions before commencement of fabrication.
Non-professional contractors will have the project specifications "reviewed" by the Purchasing Department and after winning the contract will then issue the project specs to the fabrication staff.
"There ya go, try and make us some money" with your hands tied behind your back !
Sorry if I got a bit carried away with my response.
Cheers,
Shane

 

[CWEng]

Re: Testing of plates shall be in accordance with the code.
If your code is ASME Section VIII Div 1, then the only testing requried is impact testing, when it is required for the vessel. So your contractor is correct.