We have a WPS of P No 8 with 8mm thk. But in our production we have a set on nozzle (weld-o-let) with max thk of 25mm(Full penetration Butt weld+ cover Fillet weld), shell thk is 12mm is it required to qualify a new WPS? or Can i use the same WPS

qaqcmpm;

In my opinion, you would need to qualify an additional WPS. If you read very closely QW 202.4 Dissimailar Base Metal Thickness, I think you'll realise it is saying you might have used your existing WPS IF one portion of the joint was 8mm (limit of your existing WPS) and the dissimilar mating material is greater, fo example 25mm.

But in reading your situation, it sounds like BOTH of the materials you propose to weld exceed your WPS limitations. See below, in red:

We have a WPS of P No 8 with 8mm thk. But in our production we have a set on nozzle (weld-o-let) with max thk of 25mm(Full penetration Butt weld+ cover Fillet weld), shell thk is 12mm

To be more precise, please clarify what was the thickness in supporting PQR. But it is evident that as per your information, you can not use existing WPS of 8 mm. You need to qualify another PQR considering thickness limits specified in Procedure Qualification of Section IX.

You also need to make sure that WPQ meets the requirement of Performance Qualification Diameter limits specified in Section IX. Please note that weldolet joint is normally done in 2F position. WPQ should meet the requirement of all essential variables such as without backing, without gas backing, diameter limits as well as thickmess limits. Also take care of F number since it is different for GTAW and SMAW. In case of dissimilar thickness, higher thickness shall be considered.

he important thing is that (which many people do not follow) the weldlet joint is butt joint at 90 degrees.

Surendra Ghate.

[quote="jon20013"]qaqcmpm;

In my opinion, you would need to qualify an additional WPS. If you read very closely QW 202.4 Dissimailar Base Metal Thickness, I think you'll realise it is saying you might have used your existing WPS IF one portion of the joint was 8mm (limit of your existing WPS) and the dissimilar mating material is greater, fo example 25mm.

But in reading your situation, it sounds like BOTH of the materials you propose to weld exceed your WPS limitations. See below, in red:

We have a [color=#FF0040]WPS of P No 8 with 8mm thk[/color]. But in our production we have a set on nozzle (weld-o-let) with [color=#FF0040]max thk of 25mm[/color](Full penetration Butt weld+ cover Fillet weld), [color=#FF0040]shell thk is 12mm[/color][/quote]

Hi qaqcmpm,

for this set-on nozzle we assume:
Impact testing is not required by the design code.
This is a joint between dissimilar base metal thicknesses.
Base metal thickness T1=25 mm is the thickness of set on nozzle (weldolet).
Base metal thickness T2=12 mm is the thickness of the shell.
Thickness of the deposited filler t1 is the thickness T1 plus throat thickness of the cover fillet weld.

The following paragraphs have to be considered:
QW-200.2(f) Multiple WPSs with one PQR / Multiple PQRs with one WPS,
QW-202.2(c) Qualification for Fillet welds,
QW-202.4 Dissimilar base metal thicknesses,
QW-403.8 Base metal thickness qualified,
QW-404.30 Deposited filler metal thickness qualified.

Your 8 mm PQR qualifies for:
-base metal thickness: 1.5 mm to 16 mm (QW-403.8 with reference to QW-451)
-deposited weld metal thickness: max.16 mm (QW-404.30 with reference to QW-451).
That means the thicknesses of the nozzle and of the deposited weld metal are out of the qualified range.

We can qualify your joint with one additional PQR. A butt welded test piece, base metal min. 12.5 mm thick and deposited weld metal min. 12,5 mm thick. A 12.5 mm PQR qualifies for:
-base metal thickness: 5 mm to 25 mm (acc. to QW-403.8 with reference to QW-451)
-deposited weld metal thickness: max. 25 mm (acc. to QW-404.30 with reference to QW-451)

The WPS supported acc. to QW-202.2(f) by both above mentioned PQR’s has a qualified thickness range as follows:
-base metal thickness range: 1.5 mm to 25 mm
-deposited weld metal thickness: max. 25 mm

That means both member and the weld metal are in the qualified ranges. Please note the throat thickness of cover filet weld don’t be considered because a groove weld PQR qualifies for all fillet weld thicknesses (QW-202.2(c) ).

An alternative qualification with one PQR acc. to. QW-202.4:
Weld a test coupon with two plates of dissimilar thicknesses e.g. with a single V-butt joint or double –bevel butt joint preparation and use the qualified thickness ranges of T1 and T2 as per QW-202.4.
In any case the thicker member doesn’t be tapered 1:3 (18° or less) to the thickness of the thinner member. Because this tapered transition will be not considered as a joint of dissimilar base metal thicknesses.


Note to the statement of svghate:
A joint of a nozzle (axis of the nozzle normal to the shell axis) to a shell with full penetration groove weld is not a butt joint. This is a corner joint. Please note each butt joint is a groove joint butt not vice versa. Please find below the applicable definitions of ASME VIII/1:
“MANDATORY APPENDIX 3
DEFINITIONS
joints: for the purpose of this Division, the following definitions are applicable:
(a) angle joint: a joint between two members located in intersecting planes with an angle greater than 30 deg but less than 90 deg.
(b) butt joint: a joint between two members located in intersecting planes between 0 deg and 30 deg, inclusive.
(c) corner joint: a joint between two members located in intersecting planes at approximately 90 deg.”

_________________
Kind regards,
Juergen Fleischfresser

Mr Juergen Fleischfresser,

In your reply you have mentioned both the nozzle (25mm) & weld metal deposit both are out of range. Weld metal deposit is out of range - I agree. But as per QW 202.4 (b) (1)


So how the thicker member (nozzle ) is out of range? Pls clarify?

your weld metal thk (t) is only out of range (if it would have been set in type nozzle you might escape w/o new qualification)

Base metals are qualified, no problem for base metal thickness (T)

_________________
Raghuram