Prequalified CJP weld on Tubular connection questions

By ssbn727 (*****)

Date 09-18-2014 20:52

Here's an answer for you:

TTTTTTTTTTTT    Y Y Y Y    K K K K
TTTTTTTTTTTT Y Y Y Y K K K K
T T    Y Y Y Y    K KK K
T T    Y Y   Y K K K    <<<<<<<<<<<<<<<<<<<<< T, Y, K Connections
T T YY YY    K KK K
T T    Y Y    K K K K
T T    Y Y    K k   K K
T T, Y Y,    K K    K K

ENOUGH SAID! I'm going to defer to let someone else answer this: "In order to be prequalified: It should be that one tube (Tube 1) jointing another main tube(Tube 2) without the main tube having matching hole cut, right?" because I need to take a nap from all of the exercise I did today @ Pulmonary rehab...I'm falling asleep as I type..........Snore.

Respectfully,
Henry

By kevinC

Date 09-19-2014 05:54

Following the idea, I guess it becomes a question of what is considered to be a TYK joint. I have a hard time understanding this after researching into Google.

Is it:

TTTTTTTTTTTT Y Y Y Y    K K    K K
Y Y    Y Y    K K K K
TTTTT    TTTT Y   Y Y   Y    K K K K
T T    Y   Y Y Y    K KK K
T T Y   Y   Y    K K
T T Y    Y K    K
T T    Y   Y    K K K    K
T T    Y   Y    K K   K K
T T, Y   Y, K K    K K

?
Or:

TTTTTTTTTTTT    Y   Y Y Y    K K K    K
TTTTTTTTTTTT Y   Y Y Y K K K    K
T   T    Y   Y Y   Y    K KK    K
T   T    Y   Y   Y    K KK K
T   T YYYYY K KK   K
T   T    Y   Y    K K K    K
T   T    Y   Y    K K   K K
T   T, Y   Y, K K    K K

?

For Welding purpose? My design is not using it to transfer any flow or anything, just for structural purpose.

By welderbrent (*****)

Date 09-19-2014 06:28

Oh my, you guys need Al with his auto-cad. Too funny for me at this time of night.

He Is In Control, Have a Great Day, Brent

By ssbn727 (*****)

Date 09-19-2014 14:40 Edited 09-19-2014 14:43

Hi Kevin,

It's the first one I posted... why? Think about it for a minute and ask yourself this... AWS D1.1 is a structural welding code - correct? So understanding ths, it makes sense to presume that we are talking about a structural joint as opposed to a pipe/tube joint whereby some medium, whether it be gas, liquid, or even slurry is being transmitted through the pipe/tube and into the adjoining pipe/tube which would then call for the need of having a hole on the main pipe/tube in order for the medium to be transmitted from one pipe/tube to the adjoining pipe/tube...

Now that we clarified what the intended service is for the joint in question, we can presume this: It should be that one tube (Tube 1) jointing another main tube(Tube 2) without the main tube having matching hole cut, right? - would be correct - unless of course there a note in the contract drawing(s) indicating with a detailed drawing showing the hole from one view that includes a center line going through the main tube starting from the axis of the other tube... There would also be hidden line representing the edge of the hole on the drawing and clearly indicating that a hole is to be cut prior to joining the 2 tubes together...

I mean it doesn't make sense to cut the hole out afterwards if the intent is to transmit some sort of medium through one tube into the tube that it's joined to...
Clear as mud eh? Oh well, eventually you'll figure it out.. It's busy morning for me so I got to run.

Respectfully,
Henry

By 803056

Date 09-20-2014 02:47

My tubular connections always have holes in them, intentional or not.

Al

By ssbn727 (*****)

Date 09-20-2014 04:14

I agree if the contract drawing specifies that a hole is to be cut where the members are joined together but, that's not a mandatory practice unless it's a shop standard or a specified field practice dictated by the contract drawings of the project... And usually found in the general notes sometimes with a detail drawing of the joint included also...
It also depends on whether or not the joint(s) are subject to either static or cyclical loads, but that's above my pay grade to decide and is usually left to the EOR (Engineer Of or On Record) to make that call... So under some situations it is considered a requirement, and should be expressed as such in writing to CYA before making the hole in the tube :eek:

Respectfully,
Henry

By welderbrent (*****)

Date 09-20-2014 04:30

Henry!! Tubular=holes, at the least, one in each end. Just making sure. It did not appear that you got it.

:lol:

By ssbn727 (*****)

Date 09-20-2014 08:09 Edited 09-20-2014 08:14

Brent! Pay attention to the question and don't read too much into it... now, let's look at the question again from the OP...

"In order to be prequalified: It should be that one tube (Tube 1) jointing another main tube(Tube 2) without the main tube having matching hole cut, right?"
The OP is asking if he needs to have a matching hole cut on (Tube 2) where (Tube 1) is going to connect with (tube 2) the main tube, in order to make a "T" connection where one tube is perpendicular with the other one and tube one gets welded to the center of the length of tube two... Yeah I know what Al was trying to imply, but I just wanted to clarify what the OP was seeking guidance for with his situation in order to avoid confusing him, so I didn't bite on the bait. :grin:

P.S. How does the description "open end round, or circular tubing" grab you? Holes... Okay - if you say so - yeah right!!! :roll:

Respectfully,
Henry

By 803056

Date 09-20-2014 13:54

We sometimes call them hollow beams.

Most structural tubular connections would not have a hole cut into the wall of the main member. Such a hole would reduce the strength of the main member and require substantial reinforcement. Essentially, the reinforcement would have to replace the volume of metal removed by cutting the hole in the main member. A parallel would be the reinforcement required around a manhole in a pressure vessel.

Best regards - Al