valve documentation 2

[mustafa2014]

Dear ALL, Good day,

In our off-shore project, contractor offer gate valves rating 7.500 psi instead of our requirement which was API valves 10000psi.

we accept that , My question could we ask for "stress limit calculation report" since the different of the rating effect stress of the valve.
Please your help.

 

[gerhardl]

Hello mustafa2014!

You describe the project as 'our project'. There are some different situations you have to consider.

1. If you are the end user as well as the decision maker, and the product offered deviates from the one described in the query, you can in principle ask for any reasonable extra documentation to qualify the product.

2. If the contractor is bidding parallell to other contractors and you now consider lowering the class and specification on valves, and no decision on final contractor has been made, the other companies should also be invited to alter or add to their offers.

3. If other companies (end user and/or including certification companies) have a final say for the valves mentioned or for the completed construction, all documentation, products and alterations have to be authorized by those, before the decision for change.

4. Any extra documentation should be according to an exact standard-description given by a standardizing authority, like API, ANSI or other relevant companies.

Good luck.

 

[LittleInch]

Mustafa,

I assume this is related to your post in June. API rating 7500 does not exist, therefore you needs to ask for the valve design and test qualification to show how this rating was achieved and tested. Test pressure for such a valve is 11,250 psig.

Using non standard valves had better be worth the coat saving....

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