B31.1 groove weld prep quetion 1

[USAeng]

Weld preps for groove welds joining 2 pieces together according to b31.1

"127.4.2 Girth Butt Welds
(A) Girth butt welds shall be complete penetration
welds and shall be made with a single vee, double
vee, or other suitable type of groove, with or without
backing rings or consumable inserts. The depth of the
weld measured between the inside surface of the weld
preparation and the outside surface of the pipe shall
not be less than the minimum thickness required by
Chapter II for the particular size and wall of pipe used."

Does this just mean that the groove weld must be at least the wall thickness of the pipe? What would a correct weld prep look like according to b31.1? Would the bevel have to go all the way through the wall thickness to be considered a weld prep for full penetration? We would prefer the depth of bevel to be about 1/2 wall thickness with no root opening, but I am not sure this will work with this code. Thanks.

 

[metengr]

What this means in simple terms is that the groove weld must be full penetration (full wall thickness). How you accomplish it is provided by examples of groove geometries.

 

[desertfox]

Hi USAeng

My understanding of a full penetration weld is that it would be the full wall thickness of the joint.

http://www.esabna.com/euweb/oxy_handbook/589oxy12_3.htm

I believe the dimensions of the weld preperations should be in the code your working too.

desertfox

 

[USAeng]

those dimensions are what I am missing... I cannot find them... I will look more, if anyone knows where they are please let me know

 

[USAeng]

I thought it would be in chapter II as it seemed to reference that but I looked through that chapter and couldnt find anything...

 

[USAeng]

oh and sorry for the mispelling on the title... quetion=question haha

 

[metengr]

These are examples of full penetration grooove welds from above...

Girth butt welds shall be complete penetration
welds and shall be made with a single vee, double vee,
or other suitable type of groove, with or without backing
rings or consumable inserts.

 

[USAeng]

I think I found the basic answer to my question in another answer you gave metengr... the wps will show the weld prep and all other info and that will in fact show by actually welding that the thickness of material with the weldprep will have complete penetration. So a single V with no root opening that is approx 1/2 the wall thickness is fine as long as the wps is made showing it and pqr shows that it made full penetration... but I guess another question is can you get full penetration in a 3/4" pipe without melt through? would you have to use some kind of backing ring to achieve full penetration?

 

[gtaw]

ASME/ANSI B16.25 is the document you are looking for.

In general, the groove angle is 75 degree and the root opening and root face are equal to the diameter of the filler metal used if using either SMAW or GTAW.

AWS also offers recommended practices for pipe welding. They have a recommended practices available for carbon steel, aluminum, and high chrome steels (stainless steels). They are the D10.X series of publications.



Best regards - Al

 

[USAeng]

thank you... I do have d1.1 but I will look into getting d10.x series as well as the asme spec