PQR & WPS MDMT change to lower temp 2

[dexterdweller]

I have an existing PQR & WPS that has an MDMT of -20°F can I have Charpy Testing done on a coupon for -40°F using the same welding process etc and amend the PQR or at least the WPS that I need to use for one project? ASME Section VIII Div. 1

 

[JStephen]

See QW-401.3.

 

[david339933]

Short answer yes. Usually don't have an MDMT associated with a WPS as this is established by the construction code. Can be below -20F without need to impact test.
See QW-401.1, 401.3 doesn't exist.

 

[FormerAIS]

Agree with above comments.

One thing to add, never 'revise' the PQR. Create a new one.

A PQR is intended to be written once, and never revised. Really the only reason to ever revise it would be if there were an administrative error discovered on the PQR that could be proven with other records (i.e.- spelling, decimal point, etc). Even in the case of a company name change, the PQR should have an amendment attached (or a separate document generated to cover all welding documents) to clarify on a given date the company name change.

Quality is not an act, it is a habit - Aristotle

 

[CWEng]

ASME Section IX says a PQR can be corrected, amended, or have additional information incorporated. If you do a new test, you should have a new PQR, but if you have additional test plate remaining from the first PQR that you can test at -40F, you can add that to the original PQR.

 

CWEng,
That works if the parameters have been recorded such that supplementary essential variables can be specified.
My practice back in the day was to record detailed parameters, regardless of whether impacts were required or not, and then archive a few inches length of excess weld for any future exigencies. On carbon and alloy steels I did hardness testing as a matter of course.
Good WPS design means choosing the lowest temperature for impact testing that can be confidently repeated for the grade of base metal, to cover off the lowest MDMT that can be anticipated in future. For carbon steels that is typically -40°F. It is infuriating to have to repeat a WPQ because the previous WE only tested to the requirements of the contract he was working on.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."