How can weld full penetration thickness 1.6mm by GTAW manual process

[Thuhuongengineer]

Dear My friend,
I have sigle V joint thickness 1.6mm, OD: 12.7mm. How can to weld??

 

[metengr]

Use the GTAW process for this thickness and OD.

 

[Tmoose]

what material(s) are being welded?

 

[stanweld]

Why the single V joint? A square bevel can be used. If the pipe were made of austenitic stainless, I would use automatic, orbital, autogenous equipment if I had numerous welds to make.

 

[Thuhuongengineer]

Tmoose: Stainless Steel ASTM 316 316L.

Stanweld: Yes, we can use square bevel, In my company dont have automatic, orbital, autogenous equipment, only have GTAW manual processs. We try to manny time but can not weld.

 

[fegenbush]

12.7mm (1/2") diameter 1.6mm (0.063") wall is standard sanitary tube thickness, so my recommendations are based on welding sanitary tube, your requirements may vary.

-Cut each tube square. This may seem obvious, but the ends must be cut squarely and burr free for the process to work. This can be done with an orbital cold saw.
-Fit-up the tubes with no gap.
-Setup the gas purge. This is an argon purge with a low L/min (CFM) flow rate and a hole to ensure the gas is not trying to escape from the area to be welded as you are closing the weld.
-Use no filler metal, a sharp tungsten, and appropriate amperage (40A is a good starting point).
-Keep the torch on an area until you see the material look as if it is going to fall in, then move to the next. This will happen more quickly as the tube heats up.
-Practice, practice, practice.

 

[stanweld]

If you are in a production mode with numerous welds to make, purchase or rent the appropriate, automatic equipment.

 

[berkshire]

One item that will take a lot of the pain out of hand welding small tubes like this, is a rotary welding table.
B.E.

You are judged not by what you know, but by what you can do.

 

[vanci]

Welders can also be "rented" along with the orbital welding equipment if your shop does not have the skill level to operate.

 

[Guest102023]

I agree with all of fegenbush's advice, including no filler metal. However this application begs for automation due to the high degree of difficulty welding on such a small tube diameter.

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[DekDee]

fegenbush / brimstoner,
I agree with all of fegenbush's advice but I would query the no filler metal.
Having welded miles and miles of s/s tube (dairy factories and breweries) in NZ I would always use the bare minimum of filler wire - on that OD a few "dabs" with a 1.6 mm wire.
As the addition / deletion of filler metal is an essential variable (I am presuming we are talking ASME IX) you would need a separate PQR/WPS for autogenous welding whereas an existing s/s PQR/WPS could be used if you were adding filler metal.
Regards,
DD

 

[gtaw]

Hello DekDee. Have you had a chance to watch the Americas Cup Races?

I watch the race between the US and NZ. What a nail biter! Those boat literally fly around the race course on hydrofoils!



Best regards - Al

 

[DekDee]

Hello Al,
Still in Malaysia (where it is not televised) so just catching news reports.
Got my fingers crossed for the kiwis though,
Cheers,
DD