Charpy impact temperature

[jrtei]

Qualifying a PQR for supplemental essential variables (impacts) to Section IX & Section VIII Division 1 UG-84 for minus 20F MDMT. If the actual impacts are subsized below the 80% rule you have to incorporate an additional temperature drop for the impact tests.
That PQR is still only qualified for minus 20F, correct? Or is it qualified to the lower temperature you tested at?

 

[metengr]

This only applies to testing temperature and not MDMT. If you test for -20 deg F MDMT and you use subsize CVN specimens, the test temperature must be adjusted for the smaller CVN specimen.

 

[jrtei]

Thanks, that's what I thought. While I have you here maybe you could answer another one associated with this.
Maximum heat input is another supplementary essential variable. When you have a multi process PQR (GTAW/SMAW for example),should the WPS have separate limits for each process?

 

[metengr]

Yes. Read Section IX please.

 

[jrtei]

Sorry I hit submit unintentionally, I meant to expand on that.
What about when you have 3 PQR's to cover a certain thickness range. Should your max heat for an individual process be an average heat of all 3 PQR's? Or should it be the highest (or lowest?) heat PQR?
Or would you assign a maximum heat input to each qualified thickness range per QW-403.6?

 

[weldstan]

Your last sentence applies.