Using plate to qualify PQR

[Thuhuongengineer]

Hi Everybody,
we cannot buy Tubular (TMCP) to qualify PQR so we have to use plate. But if we use Plate to qualify PQR, we will qualify 3 procedure 2G, 3G, 4G to cover all position. The other hand, we cannot weld OD Tubular less than 600 mm. How to solve this problem

 

[Mr168]

You will need to either buy tubular material that will qualify the diameters that you need, or qualify using the production tube material. No matter how you slice it, qualification on plate will not let you weld <600mm OD for groove welds. Your other option is to request that the Engineer accept a qualification to an alternate Code that permits plate material to qualify you for tube/pipe, like ASME Section IX.

 

[drumsdw]

What code of construction are you qualifying to? Some codes of construction give the option of prototype welding qualification if part dimensions, material type are not of adequate sizing. I have used this option is the past, but you can also ask the engineer to use an alternate standard for the qualification. I have had to use AWS B2.1 before and ASME Section IX materials are classified as listed base metals in this code as well.

Hope this helps,