ASME sec IX WPS & material thickness range 2

[moe27]

We need to weld a lift lug onto a block of steel. The lift lug is A516 GR70 1" thick x 6" wide X 8" tall.
The block is A517 GR70 6" thick 24"x24" sq and the lug will be a full pen weld centered on this sq block.
Which of these 2 material thicknesses must the WPS meet? A WPS that covers a material thickness range up to 1"
or one that covers a range greater than 6"?

Regards,

moe27

 

[metengr]

You should qualify a groove weld WPS for 8" maximum thickness to account for the other base material. See Section IX for weld coupon thickness qualification ranges - Table QW-451.1. A 1.5" weld coupon thickness with similar groove weld thickness deposited qualifies the WPS for 8" maximum thickness.

 

[moe27]

Thank you metengr,
That is the same answer I am getting else where. Here is what I don't comprehend,say we have an even thicker plate to weld the lift lug onto why does the thicker plate take precedence over the thinner plate when the thinner plate is 100% affected by the welding and the thicker plate has only a fraction of its thickness is affected by the welding??

Regards,

moe27

 

[metengr]

moe27;
Unless I am missing something, you are joining two base materials of unequal thickness - the lug and a block of steel. Why would you think the block base material thickness is irrelevant? You are welding to the base material directly using a partial penetration groove weld. The entire thickness for this groove weld must be considered when joining base materials of unequal thickness.

Look below from Section IX, especially what I have underlined that is applicable

QW-202.4 Dissimilar Base Metal Thicknesses. WPS
qualified on groove welds shall be applicable for production
welds between dissimilar base metal thicknesses
provided:
(a) the thickness of the thinner member shall be within
the range permitted by QW-451
(b) the thickness of the thicker member shall be as
follows:
(1) For P‐No. 8, P‐No. 41, P‐No. 42, P‐No. 43, P‐No. 44,
P‐No. 45, P‐No. 46, P‐No. 49, P‐No. 51, P‐No. 52, P‐No. 53,
P‐No. 61, and P‐No. 62 metal, there shall be no limitation
on the maximum thickness of the thicker production member
in joints of similar P‐Number materials provided qualification
was made on base metal having a thickness of
1/4 in. (6 mm) or greater.
(2) For all other metal, the thickness of the thicker
member shall be within the range permitted by QW-451,
except there need be no limitation on the maximum thickness
of the thicker production member provided qualification
was made on base metal having a thickness of 11/2 in.
(38 mm) or more.

and one other comment; thicker base material means higher cooling rate which can promote cracking of the weld deposit and surrounding base material.

 

[Don56]

Am I missing something? This is not a groove weld its a non pressure retaining fillet weld. See QW-202.2(c) and QW-451.4.

 

[david339933]

Interpretation: IX-13-16
Subject: QW-202.4, Dissimilar Base Metal Thicknesses
Date Issued: June 10, 2013
File: 13-635
Question: When employing a WPS to join flat plates of dissimilar thickness in a groove-weld tee joint, is it a
requirement of QW-202.4 that both the thicker and thinner members must be qualified within the range permitted by
QW-451 unless the alternative provided in QW-202.4 is used?
Reply: Yes.

 

[metengr]

What does this mean

the lug will be a full pen weld

?

That ain't no fillet weld.

 

[DekDee]

A 6" "block of steel" doesn't sound like a pressure retaining component.
Wouldn't this be more appropriate under AWS D1.1 (as an example) ?
Cheers,
DD

 

[metengr]

DD
Section IX is a service code book, meaning it can be applied to welding on garbage cans or any other component. It is not unique to boilers and pressure vessels.

 

[DekDee]

metengr,
I didn't say it couldn't be used - I said it was probably not appropriate.
If it is called the Boiler & Pressure Vessel code then it is intended for use on Boilers & Pressure Vessels.

"In 1911, The American Society of Mechanical Engineers established the Boiler and Pressure Vessel Committee to formulate
standard rules for the construction of steam boilers and other pressure vessels. In 2009, the Boiler and Pressure
Vessel Committee was superseded by the following committees:........"

"The Committee's function is to establish rules of safety relating only to pressure integrity, which govern the
construction* of boilers, pressure vessels, transport tanks, and nuclear components, and the in service inspection of nuclear
components and transport tanks"
Regards,
DD

 

[metengr]

DD
Yes of course. My point was there are situations where lifting lugs are commonly used in non-pressure retaining applications, perhaps like the skirt of a pressure vessel where ASME Section IX would indeed be used, in lieu of AWS D1.1. Section II, Section V and Section IX are the only book sections where they do not involve design/construction of boilers and pressure vessels directly. Instead,they support it.

I have seen Section IX invoked by owner/users and other clients on large and small turbine shells, pump casings, pump impellers, valve bodies and other components just to name a few, which are not under boiler and pressure vessel rules. That was my point.