Carbon Steel Pipe Coupons & Welding

[erikmannie]

I finally got tooled up for making 8” Schedule 40 pipe coupons. Here is the setup:

 

[erikmannie]

I am going to bevel each side at 37 1/2° (75° included angle).

I still haven’t decided whether I will have a 1/16” or 3/32” landing.

For SMAW, I use 3/32” Lincoln Fleetweld 5P+ (which is obviously 6010) for the root. Subsequent passes are 1/8” Lincoln Excalibur (obviously 7018).

I will take pictures of making the 6” long pipe coupons.

 

[erikmannie]

The parting went fine once I had my parting tool precisely squared up: 36 RPM, manual feed.

Setting the 37 1/2° angle would have been easier with 2 people.

 

[erikmannie]

Now I see that the trick to using a protractor when you’re by yourself is to:

(1) set preliminary angle,
(2) measure the angle that you set,
(3) make an adjustment,
(4) measure angle, and on and on like that.

 

[aliva]

Curious, why are you making 8" coupons? Where I used to work all welding pipe coupons were 2", for stick, TIG, whether SS or mild steel.

 

[mmcmdl]

(1) set preliminary angle,
(2) measure the angle that you set,
(3) make an adjustment,
(4) measure angle, and on and on like that.

Or just use a sine bar .

 

[erikmannie]

The mistake I made with the first pipe coupon is that I should have faced the back end before I machined the end with the bevel and landing.

Here are shots of the tapering, result before lathe file, & result after lathe file plus Scotch-Brite.

Cutting a taper:





Before lathe file/Scotch-Brite:



After lathe file + Scotch-Brite:

 

[erikmannie]

And now I notice that all the other pipe coupons that I have made in my whole life were beveled at a 52 1/2° angle (i.e. 105° included angle).





Edit: I took the time to re-taper all of the 8” pipe coupons that I had because I like a 37 1/2° bevel.

 

[erikmannie]

Curious, why are you making 8" coupons? Where I used to work all welding pipe coupons were 2", for stick, TIG, whether SS or mild steel.

Smaller coupons don’t last very long. I like a longer task.

 

[Winegrower]

Eric, I don’t even know what a pipe coupon is…do you sell these, or store them up for the winter, or what?