5" aluminum pipe

By Lawrence (*****)

Date 05-22-2013 12:28

Hi Robert, Welcome to the forum!

The first helpful thing would be to know which code your certification test would comply with. If you can get that info... Prolly somebody can help.

70 degrees is typical for a pipe bevel and if you are trying to practice, I don't think practicing on a 70 degree bevel will hurt you if the actual exam is slightly different.

When you say "sleeve" do you mean a backing ring inside the pipe?

By welderbrent (*****)

Date 05-22-2013 14:10

Robert,

WELCOME TO THE AWS WELDING FORUM!!

Lawrence, are you confusing bevel angle with groove angle? A 70* bevel angle, which is what Robert asked about, would be rather wide.

D1.1 recommends 60* groove angle, 30* bevel angle for tubular (see Figure 4.25 & Clause 4.12).

Now, 6G designation is why we are speculating on the application. But, MIG? A 6G in GMAW would indicate a short arc procedure which is not Pre-Qualified. I'm going to speculate once again and say you may mean FCAW-G (Flux core with a gas shield?). That or they are working to a different code which would still require PQR's for GMAW-S.

We know you would be testing on pipe/tubular but without knowing the application and/or code it is difficult to give you a good answer.

Have a Great Day, Brent

By newinsp (**)

Date 05-27-2013 14:34 Edited 05-27-2013 14:44

60 degrees per D1.2

By 803056

Date 05-22-2013 15:02

Aluminum usually requires a larger groove angle than a steel pipe of similar wall thickness.

I have had good results with a 90 degree groove angle (45 degree bevel on each edge). Aluminum can be welded in all positions using the spray transfer mode. You do not need a root opening. As a matter of fact, I discourage the use of any root opening. The root face is dependent on the diameter of the filler metal (electrode) used. I've had good success with a 1/8 inch root face when using 0.052 or 1/16 inch diameter electrode.

Solvent flush the pipe before wire brushing the joint with a stainless steel bristle brush. Brush the joint as if you were using a hacksaw; push on the forward stroke and lift on the return stroke. I use acetone for the initial flush and 90% isopropyl alcohol for the final flush. A pump spray work very nicely. Remember solvents are flammable. There is no reason to burn the house down because of stupidity. Make sure you flush all tooling completely before using them and use them only on aluminum.

Best regards - Al

By welderbrent (*****)

Date 05-22-2013 15:50

Yes, I just noticed his topic line stating "5" aluminum". My bad. Sometimes the context we are looking for is in the most obvious of places...the topic line.

Al makes several good points as to procedure.

Sorry about the confusion Larry. Good call.

Have a Great Day, Brent

By Milton Gravitt (***)

Date 05-22-2013 16:48

welderbrent to put a degree on the numbers hold down Alt type in 248°.
M.G.

By welderbrent (*****)

Date 05-22-2013 17:29

Thanks Milt,

I did but I had forgotten to hit my 'num lock' key to get the right mode going. So, in order not to take time experimenting I just used the *.

It's called, 'LAZY'.

Thanks though.

Have a Great Day, Brent