Flare Bevel Groove Weld

[msdengineer]

I am looking at welding a steel bar to a flat plate. I know that I need to use a flare bevel groove weld and I see in the AISC code and AWS D1.1 what the "effective weld size" should be. In my case I have a 1-3/8" bar and a 3/8" thick plate. So following the AISC, I should have a 5/16*R effective weld size. My question is how do I specify the actual weld size on the drawing? Do I have to fill the weld flush to the bar (11/16" depth) to use the 5/16R = 0.215" effective weld size? Or am I permitted to use less depth, if so how should I specify this on the weld symbol?

See the attached drawing for clarity.

 

[DVWE]

The way I read it from D1.1 is that the only way you can use less depth is to cut and etch some test specimens and measure your effective weld size as per 4.10.5. Otherwise, the underfilled U has to be deducted if not filled flush (2.3.1.4). I believe the reason for this is that once you put (E) on a drawing, it has to be measured in production, and this isn't always possible on these types of welds. AWS will allow you this credit without testing only when filled flush.

If you cut and etch some test specimens, then you can draw it exactly like you measured it, where (E) is your actual weld size, and (S) is your depth of the bevel (0.6875"). You will see that you will not get full penetration into the root of the groove (see my attachment).

You will notice that from Table 2.1 that the welding process used may change your 5/16 R. So if you qualify it as above, you should always use the same process, and the same electrical parameters within the tolerances of your WPS.

 

[msdengineer]

Thanks DVWE

 

[gtaw]

The maximum size permitted by the designer for a prequalified flare bevel groove is listed by AWS D1.1 and is assumed to be filled flush with the "bar" or the component with the radius such as a hollow structural section.

If the designer elects to use a weld that is less than the maximum permitted by D1.1, underfilling the groove is permitted. However, the actual weld size has to be verified by measurement. There are several ways to measure the depth of underfill. Once the depth of underfill is determined, it is subtracted from the maximum size permitted (filled flush) and the difference is the actual weld size.

Best regards - Al