New WPS Qualified

Date 08-04-2005 18:21

Normally the applicable code of construction for the piping system would tell you whether you had to qualify a procedure with "supplemental essential variables".

Simply requiring the test because the material spec requires it is not a justification.

I think it would be a good idea to look further. Find out what the piping system operating parameters are. Many times the engineering group that does the material selection (based on design parameters), overlooks the requirement to specify additional testing for the welding part of the design. The fact that they selected that material, which is very tough, indicates it will see relatively low temperatures. Logically, it should also be welded with a WPS that takes that into consideration.

If a new WPS is needed (to include impact testing), it will not have any bearing on the welder certifications.

Charles

By welderette (**)

Date 08-04-2005 19:12

Thanks Chall! The code of construction is ASME B31.3. I have looked there for some link, but am not finding it. Section II SA-333 8.1 states:
"For Grades 1,3,4,6,7,9,and 10, the notch bar impact properties of each set of three impact specimens, including specimens for the welded joint
in welded Pipe with wall thickness 0f .120" and larger, when tested at temperatures in comformance with 14.1 shall not be less than the values prescribed in Table 4." This is the paragraph that leads me to believe it may be a requirement. There are three systems involved. two of them have Design parameters of 300 PSIG @ 300 deg. F and the third is 165 psig @ 450 deg. F. B31.3 328.2.1 (d) states: When impact testing is required by the Code or the engineering design, those requirements shall be met in qualifying welding procedures" . I take from this statement that if the Specs call for material that must be tested, so too must the WPS be made with this material and to the pertinant standard. But I could be reading this wrong. What do you think? Thanks, Deb

By chall

Date 08-04-2005 19:33

The reference to welded pipe (in Section IIA) is for pipe manufactured with a welded seam as opposed to seamless.

I would continue to look in B31.3.

Based on my experience, 333-6 & 1 are used specifically when the systems will be subject to lower than usual temperatures. The design parameters certainly do not warrant qualifying a procedure with impact testing. It could be that the lines will be run through an outside area that sees low temperatures during the winter. Regardless of the ambient temp, the requirement to qualify a WPS with impact testing generally comes from the construction code (or contract). I believe the paragraph you referenced, 328.2.1(d), is indicating that if required eleswhere in the code than the impact testing is required.

It's tough for me to provide any better insight, as I don't have the code with me. When all else fails, file a Request for Information with the engineer.

Good luck,
Charles

By jon20013 (*****)

Date 08-09-2005 12:21

welderette; unless I misread your question, you seemed to be referring to the weld metal itself. Is this correct? If so, you can easily buy filler metal with CVN's already done. Just not sure if I read your original question correctly. If not, CVN's are "normally" done at the same time with the PQR.

By Inspectroleum (*)

Date 08-09-2005 00:05

Hi Welderette,

Here are a couple of things out of ASME Section IX that might help you:

QW-251.2 Essential Variables. Essential variables are those in which a change, as described in the specific variables, is considered to affect the mechanical properties of the weldment, and shall require requalifi-
cation of the WPS.

Supplementary essential variables are required for metals for which other Sections specify notch-toughness tests and are in addition to the essential variables for each welding process.

QW-401.3 Supplemental Essential Variable (Procedure). When a procedure has been previously qualified to satisfy all requirements other than notch toughness, it is then necessary only to prepare an additional test coupon using the same procedure with the same essential variables, but additionally with all of the required supplementary essential variables, with the coupon long enough to provide the necessary notch-toughness specimens.

It looks to me like you need to just run a coupon for the charpy tests only.

Good Luck