Hello all,
During the first inspection campaign of a ten-year old MDEA Absorber, cracking was found by PT at 5 out of 12 longitudinal seam welds of the top head 316L (NACE)cladding. Nothing abnormal in the construction MDB documentation. The vessel has been running for 10 months after the inspection campaign and now it is under inspection again. Cracking was found to be only existing at the same 5 welds. No guarantee on propagation as no record was taken during the last inspection.
Base metal material is 516 Gr 60 (NACE), PWHT'd; media: Acid gas/MDEA
Other two MDEA absorbers were inspected and found to be free from cracking.
The questions are:
1) Are the cracks inherent from construction or Environmental Assisted Cracking, and which type are they?
2) Can they be kept as-is in case they are originated from manufacturing?
3) If repair is deemed necessary, is PWHT required or we can go for NBIC/API 510 alternative preheating method?
Photos are attached.
Regards,
BV Senior Inspection Engineer
During the first inspection campaign of a ten-year old MDEA Absorber, cracking was found by PT at 5 out of 12 longitudinal seam welds of the top head 316L (NACE)cladding. Nothing abnormal in the construction MDB documentation. The vessel has been running for 10 months after the inspection campaign and now it is under inspection again. Cracking was found to be only existing at the same 5 welds. No guarantee on propagation as no record was taken during the last inspection.
Base metal material is 516 Gr 60 (NACE), PWHT'd; media: Acid gas/MDEA
Other two MDEA absorbers were inspected and found to be free from cracking.
The questions are:
1) Are the cracks inherent from construction or Environmental Assisted Cracking, and which type are they?
2) Can they be kept as-is in case they are originated from manufacturing?
3) If repair is deemed necessary, is PWHT required or we can go for NBIC/API 510 alternative preheating method?
Photos are attached.
Regards,
BV Senior Inspection Engineer
