Another Weld Symbol question...

[EmilGies]

How do you display the difference between the following welded joints?
- nozzle/shell (CAT D) where the nozzle has the bevel and then fillet weld is applied outside.
- nozzle/shell (CAT D) where the shell has the bevel and then fillet weld is applied outside.

I am concerned about small dia pipe and understand that for VIII Div 1 if you bevel the shell it is not considered small dia (<2 7/8") but if you bevel the pipe it is. Comments?


Thank you in advance,

 

[JStephen]

Just draw the joint if there's any question. If you're note sure how to draw the weld symbol, the welders quite likely wouldn't know how to interpret it, either.

 

[weldtek]

Single bevel joints require that the symbol have a 'break' and then the arrow point to the side that bevels.
The symbol for the joint you describe wold require a bevel symbol on the reference line with a fillet symbol directly on top of the bevel symbol.
Remember that the bottom of the reference line ALWAYS corresponds to the arrow side of the joint.

 

[EmilGies]

Jstephen hit the nail on the head. Keeping things clear with an additional detail always helps. I just wondered if my understanding that the joint would have the same symbol either way I describe above. Thanks for the insight,

 

[weldtek]

Hopefully, all readers of this post understand that the symbol for the two joints described above is not the same. I'd recommend that anyone who works in the drafting field and uses weld symbols, get a copy of AWS A2.4. Detailing a joint is a good idea, but, there's no excuse for shoddy drafting.

 

[EmilGies]

Weldtek -
thank you for your response. I reread your earlier response describing the symbols and still am a bit confused. I don't have access to AWS A2.4.
Maybe I am not describing the joints good enough:
- both joints will have a full pen groove weld. Both joints will have a fillet on the outside.
One joint will bevel the hole in the shell and the other joint will bevel the nozzle.
All of my reference material for weld symbols don't really address these two different joint configs. Any help you can provide would be greatly appreciated.
Gies

 

[weldtek]

As you know beveled joints differ from v groove joints in that only one side of the joint has a bevel, with the other side being straight. Basically, A 2.4 shows that in ambiguous cases, ie a butt joint, one indicates the side to bevel by placing a break between the reference line and the arrow. In those cases where it is obvious that only one side can take a bevel, ie. a tee joint, the break isn't essential.
Getting back to the joints you describe, the break, and the arrow pointing to the side that bevels would properly indicate your intentions.
Just to add clarification, the reference line is horizontal, the break would go off of the reference line at an angle, and the arrow would angle from the break to the joint, pointing to the side that bevels.

 

[chaulklate]

Gies,
If I am reading this right, you are looking for a way to differentiate the weld symbol for weld details as illustrated in Fig.UW-16.1 (a) and (d). As you indicated, both are full penn welds; one penetrates the host, the other penetrates the nozzle neck. Whether or not I am right, I have always referred to (a) as a "saddle on" connection. I have also seen it referred to as "set on". As the weld symbol for both is the same, I have historically included the letters "SADD" in the tail of the weld to indicate bevel on the nozzle neck. No message in the tail indicates the host is to be beveled. Again, I may not be right, but all fabricators I have worked for understood and used this terminology. Hope that helps.

 

[EmilGies]

Chualklate - yes, I am refering to UW-16.1A and UW-16.1 C. So they are the same weld symbol?
SADD is how you indicate to your shop to bevel the nozzle?

As you know, when things get to be less than 2-7/8" small dia quals may come into play depending on what gets beveled.

Thanks for the continued input.

 

[codeeng]

I believe the weld symbol would be the same for both cases however if you draw what you want then there can be no mistake i.e. draw a nozzle "sit-on" then you can only bevel the nozzle, draw a nozzle "set-thro" then you can only bevel the shell. Remember weld symbols complement the drawing they don't replace it.

 

[weldtek]

Hey Guys, AWS A2.4 isn't that expensive.

 

[metengr]

weldtek provides sage advice.

 

[chaulklate]

Gies,
I finally got my head around the arrow break as put forth by weldtek and got a sketch from a colleague that clearly illustrates. Still, the arrow break is ambiguos and your welder will really need to know his stuff to execute properly. I stil think a note in the tail indicating "set on" or "set in" is your best bet.

 

[EmilGies]

thanks for the help!

 

[EmilGies]

QW-452.3 (page 142) title says "Groove-Weld Diameter Limits"
I have always understood that if you bevel the shell no matter how small the nozzle is, small dia does not come into play; bevel the nozzle and you need to refer to Section IX (above QW-452.3).
Talked with a gentleman from the National Board and he stated that basically, this title tells you what you need to know. By saying diameter limits, it is specifically telling you the set on style (or where the pipe is beveled) falls under this qualification. With a joint in which the shell is beveled you do have a hole but it does not fall under this 'diameter' text.

 

[weldtek]

EmilGies,
I concur with your contact at NB.

 

[GenB]

a vebel weld! what about call in it a groove weld and make it a lot easier to understand,
a groove weld symbol: if on the shell arrow points to the shell, if on the pipe, arrow breaks to the pipe,
Oh I hope to be right on this one!
genb