Correct welding symbol for flare bevel groove weld

Date 03-17-2008 21:11

Specifically, what dimension(s) should be included in the welding symbol for a flare bevel groove weld for a shop drawing? Clause 3.12.2.1 (4) says that shop drawings shall indicate S for PJP groove welds, but shop drawings do not have to specify S for BTC-P10 (flare bevel groove weld) details. This makes sense as the groove is an existing feature and requires no weld prep.

The welding symbol for a flare bevel groove weld in Figure 3.3 includes (E), but (E) requires calculation based on material thickness or measured bend radius. That seems like it is asking a lot of the welder on the shop floor...

What am I missing? What is the corrrect way to assure that the design intent is properly communicated on the shop drawings?

Thanks!
Bill

By 803056

Date 03-17-2008 21:36

A2.4 requires the radius of the flare bevel to be given as weld as the weld size. Neither is the welder's responsibility to determine since it is the designer's responsibility to determine what the radius is if HSS and it is his responsibility to determine what weld size is required for the design loads and whether the "given" radius is sufficient to provide the weld size based on AWS limitations given for flare bevel grooves.

I can't comment on BTC-P10 because I don't have access to D1.1 at this time.

The key issue is whether there is sufficient information provided so that the welder can produce the weld size required and the inspector can verify the preparation and end results.

Best regards - Al

By swnorris (****)

Date 03-18-2008 10:42

Bill,

2.2.5.1 PJP Grooves indicates that shop drawings will indicate the weld groove depths "S" needed to attain weld size "(E)" required for the welding process and position of welding to be used.

If your flare bevel groove is to be filled flush, take a look at 2.3.1.4 Effective Size of Flare Groove Welds and Table 2.1

All this is in the design section of the code, and should be indicated on the design drawings. It is then the detailers responsibility to include this information on the shop drawings, but, in my experience, this is rarely done properly.

By BillC

Date 03-18-2008 11:26

In AWS D1.1:2006

3.12.2.1 (4) says almost the same thing as 2.2.5.1 but ends with: (Note that this requirement shall not apply to the B-P1 and BTC-P10 details.)

In other words, on shop drawings S is not required for flare bevel groove welds.

I'm in a position where my drawings are shop drawings, but they may be used in our shop or may be sent to an outside vendor. I need to completely convey the requirements for the welder and inspector.

The joint geometry is fixed, but the weld size depends on the process assuming the weld is filled flush.

I think I need to specify weld size and add a note that the weld must be filled flush at a minimum. Any prequalified process will then provide me with a 5/16r weld size. If I need 5/8r then I need to additionally indicate that the process must be FCAW-G or GMAW.

I think that this works for welds filled flush, but it gets more complicated if the weld size is less than flush.

Any thoughts?

By BillC

Date 03-18-2008 11:03

Al wrote:
"The key issue is whether there is sufficient information provided so that the welder can produce the weld size required and the inspector can verify the preparation and end results. "

Exactly! Thus my question...

By swnorris (****)

Date 03-18-2008 12:35 Edited 03-18-2008 12:38

Bill,

Assuming the weld is not flush, the minimum prequalified weld size for BTC-P10 is equal to the tube wall thickness, provided the joint is welded with either SMAW, GMAW, or FCAW.

However, the prequalified joint details for the BTC-P10 flare bevel groove weld size is based on welds being flush, as indicated by note l .

By BillC

Date 03-19-2008 14:22

Scott,

Wouldn't the minimum prequalified weld size would be 5/16r or 5/8r, which is 5/8t or 1.25t depending on the process?

So, from your experience, what is the best way to completely convey welding and inspection requirements for a flare bevel groove weld on a shop drawing?

Thanks,
Bill