# How can I make circular tube weld preparation (In rhino or grasshopper)

How can I make tube to tube specified angle (40° or 45°) weld preparation.Tube edge weld preparation.3dm (201.2 KB)

Hey there,

Usually I tend to respond when the question is more elaborated with part of solutions or tries, but here you go

I built a line at specified degree (you might want to verify my trigonometry) then sweep it around, intersect it with outer pipe face. I tried to rebuild a closed brep, bu your pipe actually isn’t closed, so I gave up !

Cheers

PipeWeldAngle.gh (73.1 KB)
Tube edge weld preparation.3dm (172.3 KB)

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Thank you Antonine… Its working well. IS it possible to get that cutting part as separate object?

Sure !

In yellow, the cutting part out of join brep.
In red, the new face out of ruled surface.

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Thank you so much. You are great. Are you working in structural steel field?

I need to make tube weld preparation in curved tubes like below.

I see. I believe there are more efficient ways of doing this than my definition though…

I’m actually an architect

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Any ideas?

Maybe too little too late, but I was looking for a more general solution. So you are able to:

• set the radius of the tube to which the other tubes will be welded on
• set the radius and the wall thickness of the tube that needs to have the weld clearance
• the angle of the weld clearance

So you are to pick the centre axis of the tubestube weld.gh (24.8 KB) tube weld.3dm (49.0 KB)

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Perfect. Thank you so much

Hi , Is it possible to find the weld volume here?

@sajesh_pj: Yes, if you mean by weld volume the blue part.tube weld.3dm (99.4 KB) tube weld.gh (25.6 KB)

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That’s for posting this, useful definitions came out if it.

Question: are there cnc plasma pipe cutters that can do this? If so who makes them?

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This machine looks like it’s capable of creating this kind of pipe cuts: HGG Group

Amazing. Total overkill for anything smaller than a museum, but amazing.

Hi ME_Mark,

Great !! thank you so much for the support

You are correct, HGG machines are used to create such contours. We are trying to estimate what amount of weld volume is required to make such connections. We now use spreadsheets to calculate these volumes and these figures are no where near the actual weld volume consumed

It would be great if we are able to accomplish this.
These joints are known as TKY joints and AWS (American welding society) D1.1 specifies how the weld should be at these joints.

The weld profile depends on the Dihedral angle ψ
The dihedral angle ( ψ ) is the angle between the chord and brace surface along the intersection curve (Fig. 4)

• First we would have to determine the dihedral angle at various points on the intersection curve.
• Next is to apply detail A/B/C based on the angle determined

Do you think this can be achieved with grasshopper ?

Hi @sajesh_pj,

Yes I think it is possible. But it would take me (beginner in Grasshopper) a while to make something useful.
What software do you use to prepare the tubes for cutting? Does it account for the A/B/C areas?
How many members and joints are there in the structure?

Hi @ME_Mark,

They use a custom made software from HGG called PROCAM to create weld preps on the tube. Apparently here we can fill-in the main and branch tube dimensions, branch angle and dihedral angle to achieve such weld prep on tube. It makes the right preparation in A/B/C areas. I have requested some screenshots from our workshop, which I will post soon.

There would be many such joints in an offshore jacket structure: