Backing tape

Date 10-24-2009 05:29

Hi all, Could someone help me with this ? Is it considered CJP welding the outside of 7 ga. 304 s/s using backing tape inside with a root opening of .0625 .045 wire ( spray mode ). The tubing has a range of 24 in. to 144 in. Also is there a certain degree that the seams have to be apart from each other ? Thanks Jim. B

By Lawrence (*****)

Date 10-24-2009 11:20

Hey Jim.

If full penetration is required in the engineering doccument and full penetration is achieved in production, than it is CJP regardless if tape or argon or a backing ring is used.

Degree that seams have to be apart? If you are talking about root opening or included bevel angles, then that would depend on the code (if any) your work must be compliant with and the design doccuments. (you haven't provided us with that info)

By Metarinka (****)

Date 10-26-2009 14:12

it will be considered CJP if you achieve full penetration regardless of joint configuration. with a few exceptions

Now can you achieve CJP in a single pass on 7ga 304? It would be easier to run a test joint and see what issues you run into. As very people would know those specific parameters off the top of their head. Although 7 ga is relatively thick, and SS GMAW is relatively sluggish.

Is there a reason the pipe isn't being beveled?