HVAC Duct Welding

[pattimelt]

My welders showed up on an industrial jobsite without any certified welders. I need to get these guys certs but I am more familiar with AWS D1.1 for structural welding and ASME 31.1/31.3 for pipe. They will be welding ductwork but more like HVAC ductwork - in fact, they will be using 6010 rods. Does anyone know what code I need to pull to test under? D1.1 seems not to fit, nor do the pipe codes. Thanks.

 

[Ron]

Most likely you need AWS D1.3 "Structural Welding Code-Sheet Steel", although your application might not be structural in a strict sense.

You might also find that E6010 electrodes are not the better electrodes for this application. Depending on the material and the thickness, it might be appropriate to go to another welding process such as GTAW or GMAW.

 

[pattimelt]

Thanks, Ron. I agree on the GTAW or GMAW; unfortunately, they brought the stick, and that is what they want to use, so far be it from me to have them change to a method they are not familiar with using.

 

[Ron]

As they say in the drag racing world.."Run what ya brung"

 

[pattimelt]

But, now - I seem to remember that this type of rod is NOT placed in a rod oven a la a 7018 It is run 'cold' Correct?

 

[Mr168]

Correct. 6010 does not need to be kept at an elevated temperature in a rod oven.

 

[EdStainless]

now you know why they brought it, less work for them, application be damned.


= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[pattimelt]

Ah, but these are 6011, not 6010 - not familiar with these (they just brought me a box) Same scenario? AWS D9.1 section 1.4.4.2 says dried for 2 hours between 500 and 800 degrees F for A5.1 rods (which these are).

 

[dvd]

See Chapter 6. Hopefully your contractor is a member of SMACNA and has a copy. At the least they can get the member discount.

http://www.smacna.org/bookstore/pdf_toc/Welding_2006_TOC.pdf

 

[racookpe1978]

Ah, but these are 6011, not 6010 - not familiar with these (they just brought me a box) Same scenario? AWS D9.1 section 1.4.4.2 says dried for 2 hours between 500 and 800 degrees F for A5.1 rods (which these are).

And you are (probably) the first to have ever checked them on this this ... 8<)

What diameter rod are they trying to foist off? If they are attempting to weld HVAC-thick sheet metal with SMAW, it will have to be very, very small or they will burn through. Also: Stick welding is notoriously dirty and leaves a lot of grit, debris, and residue. Have they (the welders) committed to cleaning up and wire-brushing the interior AND exterior of the sheet metal before air flows through?

Have you inspected at the end of each shift the interior and exterior (before insulation goes on!) to make sure it really is welded up properly and cleaned?

 

[berkshire]

This post raises more questions than it answers.
Grease duct is heavy enough wall, to be stick welded with no problems.
Most HVAC duct unless it is an extremely large size is less than 16 ga wall, not condusive to stick welding unless you have a very steady hand and hours of experience. This is why most companies switched to mig or fluxcore.
If this is a trade union jobsite, I would suggest insisting on getting qualified welders from your SMWIA local, if non union then check with your local ABC center.
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

 

[pattimelt]

I have copped out and sent the crew back to the shop to get certified to some code - any code LOL this is an application on a large construction site for a dust suppresion system They will be using 3/32 rods and welding on 16-18 ga wall For HVAC, this is pretty big stuff Cleanup will be monitored constantly as this is a very heavily regulated site when it comes to enviromentals They are all testing today - we shall see I am trying to get a copy of SMACNA (or at least the chapter 6)

 

[Duwe6]

In my opinion, you also need a copy of AWS D1.3 to cover any zealous regulators. OSHA, etcetra is big on RAGAGEP -- "Regualarly and Generally Accepted Good Engineering Practices". No, you are not making "structural" sheetmetal items. But D1.3 is the only regularly accepted sheetmetal welder qualification code that I know of.

If you are using a Code, and following those rules, you will survive any audit, no matter how stringent. Tests are simple and can be performed on the jobsite with a saw and hammer.

 

[berkshire]

3/32" on 18 ga is pushing it for stick, they would be better off with 1/16" electrodes.
Watch for holes in the duct and soldered areas with no penetration.
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor