Welcome to the Forum 13Hz !
That's a really good question. It sounds like you are describing a skewed T joint.
But using words is always tricky,,,, But a detailer who actually is trying to get the weld symbol correct should be encouraged and helped eh?
Is this type of assembly that you are describing?
13Hz,
Welcome to the AWS Welding Forum!!
Now, if I understand both you and Lawrence correctly I think there are a couple of differences as I don't believe Lawrence's illustrations depict 'Skewed Joints' and definitely not fillets since they do not show the weld in the joint. A skewed joint would have the plate coming into the tube in such a manner that the welds would be of differing angles from the two sides, these are equal on each side of the plate to tube connection.
Having said that, I do think he has attempted to depict what you were asking. Please correct us if we have interpreted your query wrongly.
It will ultimately depend upon the total size of both the tube and the plate in order to know just how much of an opening there will actually be at the point where weld is to be deposited. It may also depend upon the welding process as even a small opening could be considered a flare bevel if using GTAW whereas it would take a somewhat larger opening to consider it anything other than a fillet weld if using FCAW with 1/16" electrode or SMAW with a 5/32 electrode.
Some of this could be an exercise in semantics but hopefully you can see what I am talking about and there can be differences in application which ultimately needs a lot more information and even pictures.
This issue can even be the case when dealing with tubing laying on it's side on a plate as you mentioned. If the tubing is square and not round you may still end up with a flare bevel if the tubing is large enough and especially as the wall thickness increases so that there is more of a corner radius. With say a 1" sq tube with thin wall it will be reasonably square and considered a T joint for a fillet weld especially for most welding processes but as the tube gets larger and thicker the radius increases to a point where it can easily be a flare bevel for some and is up for grabs unless one wants to get very picky and technical.
Rebar, round bars, tubing, all have applications of flare bevel welds and even when bringing the plate into a joint configuration as illustrated by Lawrence it can be difficult to define without much more information.
Now, to be more precise in answering your question, I don't believe the code really gets down to defining when a fillet weld becomes a flare bevel weld. But, I will have to do a little more research to see what I can find.
He Is In Control, Have a Great Day, Brent