Concerns about ASME B31.3 Socket Welds 7

[Rubje]

There appears to be a recent change (2022) to 328.5.2e. It now says the following:

"In making socket welded joints, a gap as shown in Figure 328.52b, illustration (c ) and Figure 328.5.2C shall be provided prior to welding. After welding, a gap is not required to be present or verified"

I understand it's more ideal to check the gap before welding due to expansion from the heat but this seems to be an unnecessary addition.

Can someone explain why the code was updated to mention checking the gap after welding is not required? Seems unnecessary.

 

[DVWE]

It is completely unnecessary. But, too many people in this industry cannot read or refuse to read, for whatever reason (perhaps a lack of understanding about expansion during welding) “prior to welding”. This is usually followed by, “Well, it doesn’t say anything about after welding, so we have to check for gap, because we’ve seen cracking as a result of no gap”. And suddenly, socket welds were being RT for “gap verification” post welding. Some companies even went as far as writing it into their specs. There was enough ambiguity and argumentation in industry that the committees decided to be vocal, rather than silent on the issue. Unfortunately, I was part of many of these ambiguous arguments with many different contractors and many differing opinions. Personally, I’m glad it was added in, because now no one can tell me, “It’s code.” If companies still want post weld gap verification, fine, but it better be in their specs, and I can now show people who just want it because “it’s code”, it is now in fact not.

 

[Rubje]

I'm convinced now thanks!

 

[david339933]

There has been an interpretation for years, but much better to be in the Code.

Standard Designation: B31.3
Edition/Addenda:
Para./Fig./Table No:
Subject Description: ASME B31.3 1996 Edition Paragraph 328.5.2, Welding Requirements Fillet and Socket Welds
Date Issued: 05/20/1997
Record Number:
Interpretation Number : 16-06
Question(s) and Reply(ies):
Question: In accordance with ASME B31.3 1996 Edition, paragraph 328.5.2 and Fig. 328.5.2c, what is the minimum gap acceptable in a socket welded joint after welding?

Reply: The 1/16 in. approximate gap shown in Fig. 328.5.2c is before welding. The Code does not provide a gap dimension after welding.

 

[DekDee]

DVWE,
Agree 100% with your comments.
Battling a Client at the moment who has it in their specs.
As I keep telling them if you want to spend money on RT verification do it before, not after.
Cheers,
Shane

 

[DVWE]

You have my empathy, DekDee!

Best of luck to you.

The devil is in the details; she also wears prada.

 

[DVWE]

I definitely like the new language in the new code version vs the interpretation:

“The Code does not provide a gap dimension after welding.”

vs

“After welding, a gap is not required to be present or verified.”




The devil is in the details; she also wears prada.

 

[DekDee]

Thanks DVWE,
The Client wants approx 1.5 mm before welding and then any gap under 1.0 mm after welding is rejectable.
As an ex-Radiographer I can guarantee you cannot measure 0.5 mm on a radiograph but they are not listening to me.
Even if you could get the perfect shot at exactly 90 degrees to the "run" pipe I still do not think you could measure the gap.
So we may be cutting out a shitload of welds that are code compliant ?????

 

[DVWE]

DekDee, have you tried the Gapalet route with them? I’ve had luck with a couple of different clients with them.

https://m.galgage.com/measuring_gap-a-let.html

The devil is in the details; she also wears prada.

 

[r6155]

@ DekDee
Avoid this client and replace it with a reasonable one.

Regards

 

[r6155]

If the SW is inspected with RT, in the end it is convenient to do a butt weld with RT.
SW is the worst design.

Regards

 

[ipi]

Relevant to this, is there any reference for maximum gap allowed before welding? in Socket weld type?(minimum gap is 1.5mm)

Thanks in advance

 

[r6155]

See ASME VIII Div 1 Figure UW-21 (4). 1,5mm APROXIMATE gap before welding.

Regards

 

[weldstan]

No maximum but there out to be. I've seen a multitude of failures in service due to almost no insertion. Our specs were written to insure full insertion prior to pulling back approximately 1/16" and scribing to insure pullback and gap.

 

[ipi]

Thanks r6155 and WeldStan. Once i tried putting 2 mm gap instead of 1.5mm just to be safe and the client asked me the same if there is any maximum limit. He didnt object though as there was no reference for rejection.