Plug Weld (ASME IX)

By Joey

Date 06-12-2009 03:11

D1.1 allows the groove weld. ASME IX not specified. But I guess it also allow the use of groove weld in plate or pipe.

By Bill M

Date 06-12-2009 19:21

I guess I would first determine if the current PQR you have supports this new WPS.

If so, simply write a new WPS for the plug welding.

By MBSims

Date 06-13-2009 14:36

An interesting question. ASME IX specifically discusses the qualification tests required for groove and fillet welds, but not plug welds. QW-402.1 is a nonessential variable, but it only mentions groove welds. My inclination would be to say that since a groove weld qualification qualifies for groove and fillet welds, then it should also qualify plug welds. If we were plug welding a liner to a duct, or something similar, we would use a WPS qualified for groove welds. D1.1 has the following statement in 4.29:

"Qualification for CJP groove welds on tubular or nontubular
connections shall qualify for all plug and slot
welds."

If you are doing this for a customer and they have raised a question, then you could perform a workmanship sample using the proposed hole diameter and material thickness, cut it in half across the plug, and perform a macroetch.

By bert lee (**)

Date 06-13-2009 15:22

MBSims,

thanks for your input, similar to Joey.

you mean "mockups sample". that's a good idea but for the "macroetch test".... I'm not sure if we can declare in PQR that the test was done in accordance with ASME IX.

bert

By MBSims

Date 06-13-2009 15:53

You can record it in the "Other Tests" block on the PQR. This space is routinely used to record the results of additional non-ASME tests, such as NACE MR01-75, IGSCC sensitization under ASTM A262, etc.

By bert lee (**)

Date 06-13-2009 16:25

MBSims,

if let say my client decided to use the test method and acceptance criteria as per AWS D1.1.....you mean I still need to use the ASME IX PQR format using "other Test" block on PQR.? this might cause confusion and questions from other readers who are not technically sound.

its quite complicated...should I suggest to use groove weld?

anyway, thanks

bert

By MBSims

Date 06-18-2009 23:30

I'm not really sure what you are looking for. Section IX should have already been met with the groove weld qualification you mentioned. Is Section IX the applicable code for the work to be performed? If this is a client request and they are asking for the test to be per D1.1, then you should use the D1.1 PQR form and follow D1.1. If the client has requested the plug welds be qualified per ASME IX, then there are no applicable ASME IX tests specifically for plug welds and anything you do will be per a mutual agreement between you and the client, including the test coupon configuration, type of tests to be performed, acceptance criteria and how to document the results. I see no problem using a welding procedure already qualified for groove welds and performing a supplemental PQR on plug welds (if that is what the client is looking for) using the same essential variables as the groove weld. The test could be a cross section and macroetch using the ASME IX fillet weld macroetch test and acceptance criteria as a guide. There are a number of ways to document it, but in the end the client needs to let you know what they are looking for.

By CWI555

Date 06-19-2009 00:57 Edited 06-19-2009 00:59

QW/QB-492 Definitions

plug weld: a weld made in a circular, or other geometrically
shaped hole (like a slot weld) in one member of a lap or
tee joint, joining that member to the other. The walls of
the hole may or may not be parallel, and the hole may be
partially or completely filled with weld metal. (A filletwelded
hole or spot weld should not be construed as conforming
to this definition.)

""I believe that makes it clear that fillet weld criteria does not apply."

Aws 3.0 01
Slot weld. A weld made in an elongated hole in one member of a joint
fusing that member to another member. The hole may be open at one end.
A fillet welded slot is not to be construed as conforming to this definition.
See figure 15(D).

""AWS is consistent with ASME in this.""

Back to section IX:07 QW/QB-492 Definitions

lap joint: a joint between two overlapping members in
parallel planes.

single-welded lap joint: a lap joint in which the overlapped
edges of the members to be joined are welded along the
edge of one member only.

QW-202.2 Groove and Fillet Welds
a) Qualification for groove full penetration
b) qualification for partial penetration groove welds
c) qualifications for fillet welds

-----------------------------------------------------------------------------------------------
In my opinion, both ASME and AWS make a very important distinction in the definition of "plug welds",
that gives specific direction as to what criteria to apply to plug welds for qualification. The specific
exclusion of fillet weld criteria in the definition and the inclusion of the words partial and complete fill,
would, if not directly, give direction to treat qualification the same as you would a partial or full pen.
Should this be the case, applied linings would have to have some specific redirection, or be in contradictory
to the applied definition.
The following is the direction on applied linings again in 07 IX:

That distinction is in that
QW-218 Applied Linings
QW-218.1 WPSs for attaching applied linings shall be
qualified in accordance with QW-202.2(a), (b), or (c).

QW-383.2 Applied Linings
(a) Welders and welding operators shall be qualified
following the rules for making groove or fillet welds in
accordance with QW-301. Plug welds for attaching applied
linings shall be considered equivalent to fillet welds for
the purpose of performance qualification.
--------------------------------------------------

There is the logical specific exclusion in regards to treatment/definition of plug welds.
This to me gives a specific logical path and direction.

That's my two cents worth.

Regards,
Gerald

By MBSims

Date 06-19-2009 03:28

Gerald,

A good assessment, but I'm not sure I understand which logical path you refer to. His question was "Can I use my existing WPS for groove weld to support the plug welding?" Are you suggesting the answer is "No" and the WPS must be qualified under D1.1 since ASME IX does not specifically address qualification of plug welds?

By CWI555

Date 06-19-2009 11:37

Im suggesting that while ASME IX does not specifically address it, there is enough inference for CYA to utilize the WPS (if ASME) to support it.

By MBSims

Date 06-19-2009 23:07

I agree. Just wasn't sure what path you were suggesting.