UG-84(h)(3) - Number of Specimens?

[minibenny]

Hi there,

I am having trouble interpreting the requirements of the subject paragraph. The way I interpret it, there seems to be conflicting requirements for the number of sets of specimens required. I'm wondering if someone can provide their interpretation of the number of sets of HAZ and weld metal (WM) specimens to be taken for procedure qualification on a full penetration butt joint on material greater than 1-1/2" thick.

The way I interpret paragraph UG-84(h(3) is three sets of impact specimens are required. Heat affected zones shall be as described in (g)(2). Two sets of specimens shall be removed from the weld metal, with one set within 1/16" of one surface, and one set midway between the opposite surface and the center of the coupon.
For the mumber of HAZ specimens required, I would need to refer to UG-84(g)(2), which refers to Table UG-84.6. This table requires two sets of HAZ specimens.
So, should the number of sets of specimens required per UG-84(h)(3) be four (2 WM, 2 HAZ) for test material > 1-1/2" thick?

 

[david339933]

09/20/1988
Record Number: BC88-134
Interpretation Number : VIII-1-89-21
Question(s) and Reply(ies): Question (1): When procedure and/or production impact testing are required on material over 1½ in. thick and the material is not exempt from impact testing, are two sets of impact specimens from the weld and heat affected zones required?
Reply (1): Yes.

 

[david339933]

Why not do only bends/tensiles on 1-1/2" coupon and do another PQR on a thinner BM thickness using the same parameters as the 1-1/2" coupon and run only impacts? Otherwise, your min. qualified thickness will be 5/8".

 

[minibenny]

Thank you for the replies david339933.
I found that interpretation when looking into my question also. I thought it was odd that the current Edition of ASME VIII-1 still says (3) sets of specimens required in UG-84(h)(3). I would think it would be changed to say four sets of specimens required, to include the number of sets of HAZ specimens with Table UG-84.6.
I intend to follow what is noted in the interpretation you referenced. I'm just wondering if anyone could explain why UG-84(h)(3) still says three sets.

I appreciate the input of welding another thinner coupon to broaden the range of qualified BM thickness, but at this time the intention is to only qualify for what we need for a particular job due to time restraints.

 

[metengr]

The reference means impact testing is performed on sets of three impact test specimens as required by UG-84(c)(1).

 

[minibenny]

metengr, perhaps I am misunderstanding your reply or the Code paragraphs, but both UG-84(h)(3) and Table UG-84.6 both specify the number of sets required. I understand that 1 set = 3 specimens. UG-84(h)(3) appears to say both 3 sets and 4 sets are required. Which is it?

UG-84(h)(3) says "....three sets of impact specimens are required". Following this, locations for two sets of weld metal specimens are described, and reference to UG-84(g)(2) is made for heat affected zone specimens, which refers to Table UG-84.6.
Table UG-84.6 requires two sets of HAZ specimens for base metal thicknesses equal to and greater than 1-1/2".
Since paragraph UG-84(h)(3) applies only to materials over 1-1/2" thick, wouldn't the two sets of HAZ specimens described in Table UG-84.6 and two sets of weld metal specimens described in UG-84(h)(3) be mandatory, meaning a combined number of HAZ and weld metal sets equaling four sets of three specimens? I don't understand why (h)(3) would say three sets required.

I guess by "...three sets are required" in UG-84(h)(3) could mean
i) one set in weld metal within 1/16" of one surface
ii) one set in weld metal 1/4t to 1/2t from opposite surface
iii) from whatever number of sets for HAZ specimens are specified in UG-84(g)(2).

If this is the case, UG-84(h)(3) seems, to me, to be slightly misleading.

EDIT: I noticed the Topic of my Thread should have been "...Number of Sets of Specimens?" not "...Number of Specimens". Sorry for the confusion.