Acceptance Criteria for Excess Penetration

[nktqc]

Hi friends

Well in Pipeline Radiography of a butt joint what is the acceptance criteria for Excess Penetration.

Kindly note that , we are not able to check weld joint from Inside and code we are following is API 1104.

 

[eyec]

look @ section 6.3.6 Burn Through

 

[nktqc]

Dear Eyec

Thanks for your comment but BT ( Burn Through ) come due to excess penetration but its not classified as excess penetration.

What API 1104 says - A burn-through (BT) is defined as a portion of the root bead where excessive penetration has caused the weld
puddle to be blown into the pipe.

 

[SJones]

Why are you looking for excess penetration when the welding standard does not require you to? The acceptance criteria are usually stipulated in the end user's supplementary specification. Measurement in production welding is problematical but is sometimes achieved using density comparisons with standard radiographs of acceptable welds taken during procedure qualification.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[nktqc]

Mr. S Jones

You are right that if code is silent then no need to ask , but excess penetration is a defect , and the same code is giving range for Re-inforcement ( outer ).

yes Density difference is a concern based on that we can take a decesion. But is there any thing specific ?

Thanks for your sugetion.

 

[SectionIX]

Burn through is not excessive penetration. By its nature, a burn through is an area of less weld metal, not more.

If you are looking for an acceptance criteria, 1104 will not be any help because the only criteria for reinformement is for the outside surface.

 

[SJones]

If you are looking for some notional value of acceptance criterion, it is dependent upon the end user's requirements. Typically, it starts at 3 mm and can be reduced for such things as sour service or intelligent pigging requirements. If you have not been given a number, it should not worry you.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[nktqc]

Thanks Jones

Well i have to look for pigging requirements

thanks , thanks to all

 

[nktqc]

Friends,

I got the requirement for excess penetration from Shell DEP - DEP 61-40-20-30 1993 amendments to API 1104

6.3.6 Burn through
Change title to:
6.3.6 Burn through and excessive penetration
Add the following:
6.3.6.4 Root penetration shall not exceed 3 mm.

 

[eyec]

2009 version says

"The maximum depth of root pass penetration shall be 1.6 mm."

 

[nktqc]

oh , let me check.

Thanks Eyec

 

[nktqc]

i have 2010 edition where its not mentioned , well i will try to get. Any way thanks a lot.