weldinguide.com

all about welding





Dissimilar base metal thickness as per ASME IX

Dissimilar base metal thickness as per ASME IX

Postby gerdmil » Thu Nov 14, 2013 10:46 am

Dear all,
Could you please let me know the range of base metal thickness qualification of a butt weld PQR that was performed using from one side plate with thickness 6 mm in material ASTM A 240 type 316 and from the other side plate with thickness 15 mm in material ASTM A 516 Gr 60?
thanks
gerdmil
Last edited by gerdmil on Sat Nov 16, 2013 4:29 pm, edited 2 times in total.
gerdmil
 
Posts: 9
Joined: Fri Jul 12, 2013 10:21 am

Re: Dissimilar base metal thickness as per ASME IX

Postby Hrushikesh » Fri Nov 15, 2013 3:21 pm

Dear Gerdmil,
As per QW-202.4 "Dissimilar Base Metal Thicknesses" and QW-451 "Procedure Qualification Thickness Limits and Test Specimens" the thinner member will be qualified 1.5-12 mm (for Base metal) and up to 12 mm (for weld metal). For the thicker member 5-30 mm (for base metal) and up to 30 mm (for weld metal). Please reply your interpretation.
Hrushikesh
 
Posts: 11
Joined: Fri Aug 23, 2013 2:54 pm

Re: Dissimilar base metal thickness as per ASME IX

Postby mohd » Fri Nov 15, 2013 9:14 pm

dear one,

moreover to hrushikesh,
for qualification range please follow also the weld deposited thickness "t" requirements.

regards,
mohd.
mohd
 
Posts: 74
Joined: Mon Jul 08, 2013 2:17 pm

Re: Dissimilar base metal thickness as per ASME IX

Postby gerdmil » Sat Nov 16, 2013 4:27 pm

Dears Hrushikesh and Mohd thanks for your support,
Mohd, regarding "weld deposited thickness" in the PQR please note that it is equal to "base metal thickness" (t=T) since the PQR welding was performed on single V joint using single process (GMAW) with back-gouge.
Hrushikesh, I have seen the suggested by you QW-202.4 but I am not sure if it is applicable to my case since this clause is for production welds between dissimilar base metal thicknesses based on a qualified procedure that has been performed on a test coupon with equal base metal thickness to both of its sides as implied by the first column (thickness T of test coupon welded) of table QW-451.1. In my case the procedure qualification has been done using test coupon prepared by base metals with dissimilar thicknesses (T1 and T2). So, could you please give me your opinion?
regards
gerdmil
gerdmil
 
Posts: 9
Joined: Fri Jul 12, 2013 10:21 am

Re: Dissimilar base metal thickness as per ASME IX

Postby wefel » Fri Nov 22, 2013 10:50 am

Gerdmil,
Even though the table QW-451.1 says in the first column "thickness T of test coupon welded", the code doesn't restrict to qualify procedure only on base metals with equal thicknesses. Please have a look to the attached ASME interpretation IX-04-11 which makes clear that a procedure qualification can be performed using base metals with different thicknesses. As you have mentioned the QW-202.4 is applicable to production welds between dissimilar base metal thicknesses but the supporting PQR can be done using base metals either with equal or unequal thicknesses.

Hrushikesh,
Please let me disagree with you since according to QW-202.4 there are two separate cases that we have to investigate.
case 1
For the production weld the thicker part is the material ASTM A 516 Gr 60 then you qualify for thickness:
ASTM A 516 Gr 60: 5 mm up to 30 mm (as per QW-202.4 (b)(2))
ASTM A 240 type 316: 1.5 mm up to 12 mm (as per QW-202.4 (a))
case 2
For the production weld the thicker part is the material ASTM A 240 type 316 then you qualify for thickness:
ASTM A 516 Gr 60: 5 mm up to 30 mm (as per QW-202.4 (a))
ASTM A 240 type 316: greater than the thickness of material ASTM A 516 Gr 60 up to unlimited thickness since the material ASTM A 240 type 316 has been assigned P-number 8 and the qualification was made on base metal with thickness 6 mm (as per QW-202.4 (b)(1)).
So, by the combination of case 1 and case 2 it happens that the range of qualification regarding thickness is:
ASTM A 516 Gr 60: 5 mm up to 30 mm
ASTM A 240 type 316: 1.5 mm up to unlimited thickness
Attachments
Interpretation IX-04-11.pdf
(36.03 KiB) Downloaded 401 times
wefel
 
Posts: 37
Joined: Thu Sep 05, 2013 1:31 pm

Re: Dissimilar base metal thickness as per ASME IX

Postby Hrushikesh » Mon Nov 25, 2013 2:23 pm

Dear Gerdmill,

Thanks for the knowledge sharing. It was really an healthy discussion. I have a question.
If suppose I have to use this PQR in production with dissimilar thickness, what base metal thickness range should I give in WPS? Will it be 1.5 mm to unlimited thickness? Please send your interpretation.

Thanks
Hrushikesh
 
Posts: 11
Joined: Fri Aug 23, 2013 2:54 pm

Re: Dissimilar base metal thickness as per ASME IX

Postby Ballbearing » Tue Nov 26, 2013 2:10 am

Wefel,
Where does the unlimited thickness come from ?
Gerdmil stated he had a PQR with P8 welded to P1.
The clause you have quoted below is applicable to "joints of similar P-Number materials"

QW-202.4 Dissimilar Base Metal Thicknesses.

(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.

Regards,
BB
Ballbearing
 
Posts: 76
Joined: Wed Jun 12, 2013 10:11 pm

Re: Dissimilar base metal thickness as per ASME IX

Postby Ballbearing » Tue Nov 26, 2013 2:26 am

Guys,
Here is my interpretation.
There are various scenarios based on the actual joint welded,
T1 = 6 mm P8 material,
T2 = 15 mm P1 material.

Single Vee (with the thicker base metal tapered to 6 mm)
qualified range of base metal T1 = 1.5 to 12 mm (actual deposited weld metal: 6 mm)
qualified range of base metal T2 = 5 to 30 mm (actual deposited weld metal: 6 mm)
maximum deposited weld metal: 12 mm

Double Bevel (Tee joint)
qualified range of base metal T1 = 1.5 to 12 mm (actual deposited weld metal: 6 mm)
qualified range of base metal T2 = 5 to 30 mm
maximum deposited weld metal: 12 mm

Double Vee (as per Wefel's attachment)
qualified range of base metal T1 = 1.5 to 12 mm (actual deposited weld metal: 6 mm)
qualified range of base metal T2 = 5 to 30 mm (actual deposited weld metal: 15 mm)
maximum deposited weld metal: 30 mm

Regards,
BB
Ballbearing
 
Posts: 76
Joined: Wed Jun 12, 2013 10:11 pm

Re: Dissimilar base metal thickness as per ASME IX

Postby wefel » Wed Nov 27, 2013 9:31 am

Ballbearing,
Thank you for your intervention to this topic since it has been proved that my interpretation was incorrect. The qualified thickness of ASTM A 240 type 316 could not be "up to unlimited" since, as you have highlighted, the PQR has not been performed by welding this material to itself but to a P-no:1 material. Likewise, I would like to thank you for your interpretation based on the three given examples that helps us to better understand the clause QW-202.4 of ASME IX.
regards
wefel
wefel
 
Posts: 37
Joined: Thu Sep 05, 2013 1:31 pm

Re: Dissimilar base metal thickness as per ASME IX

Postby Hrushikesh » Wed Nov 27, 2013 5:29 pm

Thank you ballbearing for clearing the doubts. It was really a very good discussion.
Hrushikesh
 
Posts: 11
Joined: Fri Aug 23, 2013 2:54 pm


Return to Pressure vessel, boiler & valve welding

Who is online

Users browsing this forum: No registered users and 1 guest