Minumum Weld Reinforcement Asme B31.3 1

[ctgcwiqc]

thread292-247443 "Can anyone direct me to the actual paragraph that gives the minimum weld reinforcement for ASME B31.3 normal fluid piping. I have already been to Table 341.3.2 and am having a little interpretation problem, using Symbol "L" height of reinforcement in any plane through the weld shall be with in the limits of the applicable heights value in the tabulation at right........
For example say I have a 4" sch 40 (0.237) and Tw is the nominal wall thickness of the thinner, according to note 6.....
I would use the second one >6(1/4") ≤ 13 (1/2")
So the question is the height of the reinforcement should be no greater then or no less then ≤ 3 (1/8")?
"

This answer looks to be coming way too late to answer your question in a timely manner, but you are reading the table correctly. Your max weld reinforcement at the weld root would be 1/8" for that thickness base metal. I dont believe there is a paragragh discussing this in B31.3 other than to guide you to this table. Now in regards to minimum weld reinforcement the code provides this criteria listed as "depth of root surface concavity". This is regardless of thickness that I am aware, and the answer is "Total joint thickness, incl. weld reinf., ≤ Tw". This excludes weld cap, and only uses base metal thickness for VT. On a radiography this is a little harder to grade however this is measured by density and is acceptable as long as the density of the root concavity (suckback) is less than that of the base metal.

Short andswer if performing VT inspection any amount of root concavity is rejectable. If performing RT there is a little more leeway if a heavy cap is present, masking the density of the concavity. Hope this helps andyone else looking for this answer, and please feel free to correct me if I am wrong.

 

[Kiwi2671]

ctgcwiqc,
Sorry, have to disagree with your post.
Root concavity or Concave Root Surface for NFS, Severe Cyclic and Cat D is a "K" for all.
"K" states the total joint thickness (including weld reinforcement) must be greater than the wall thickness of the thinner member joined.
So, therefore for visual inspection if you have a 2 mm high cap you can have up to 2 mm deep root concavity.
RT shows it quite clearly - if you have a dark area on the root you place the densitometer in that dark area and then compare that density with the density of the parent metal.
3 mm deep concavity (with a 2 mm cap) will give a greater density through the weld metal than through the parent metal so it is rejected.
1 mm deep concavity (with a 2 mm cap) will give a lesser density through the weld metal than through the parent metal so it is acceptable.
Hope that helps,
Regards,
Kiwi

 

[ctgcwiqc]

You are correct, I really should be more thorough. Thanks, at least now if someone searches this topic they will have valid response. I will atttempt to edit my previous post.

 

[ctgcwiqc]

Okay, I'm still rushing and cant seem to find a way to edit previous post. I'm new to posting on this forum but have found the information very useful for years. I was looking up an answer on weld reinforcement acceptance criteria for a welding foreman, and the question was un-answered on here. I had to resort to looking it up in B31.3. I found the answer, and closed the borwser, and the welding foreman recommended I answer the question. The thought had not occured to me. And the answer would not be explained for anyone looking for the answer in the future, which is why i created this thread. Long story short there is a wealth of knowledge out there, we just need to encourage people to share it. Thanks.