WPS Requalification API 1104

[perruolo]

Gents

I wonder how to interpret the changes on the essentials variables which require the requalification of the WPS. For instance: Statements like "Major increase" of flow rate; An "Increase" of time between passes; A "change" in the speed travel; A "decrease" of the minimum pre heat temperature. It is not specified a value. When should I consider a major change????? If time between passes "Increase" 1 seg, or the Pre-heat temp "decrease" 1°C should the WPS be requalified?? of course I am exaggerating.

I appreciate any suggestion

Regards

Miguel

 

[SectionIX]

PRCI published a document where their interpretation of a major increase in flow rate was +/- 20 % was considered reasonable.

An increase in time between completion of root and start of hot pass should be self explanatory.

For travel speed, their interpretation was that the travel speed shown on the WPS should be no more than +/- 20 % from the median recorded PQR value. The specified range should reflect the minimum and maximum values that produce an acceptable weld.

For decrease in preheat, if you can measure a one degree difference.....

 

[perruolo]

AsmeIX Thanks for your reply. Where can I get the document you make reference???

 

[SectionIX]

Contact PRCI at

http://www.prci.org/.

Ask for Guidelines for Interpretation and Application of API 1104.

Its pricy; $400.00 for non-members