Nashanas
Petroleum
- Apr 23, 2021
- 54
Hello,
According to ASME Sec 9 QW 408.9: The backpurging is required for a certain set of materials only. So e.g P8 materials are not required to have backpurging.
According to API RP 582 Section 7.3 backpurging is required for GTAW and GMAW for all materials above 2.25% of Cr. So P8 materials with Cr% > 2.25 are supposed to be backpurged.
Why is API more strict about back purging then ASME. Is there a metallurgical reason?
According to ASME Sec 9 QW 408.9: The backpurging is required for a certain set of materials only. So e.g P8 materials are not required to have backpurging.
According to API RP 582 Section 7.3 backpurging is required for GTAW and GMAW for all materials above 2.25% of Cr. So P8 materials with Cr% > 2.25 are supposed to be backpurged.
Why is API more strict about back purging then ASME. Is there a metallurgical reason?