Amine stress corrosion cracking 1

[0481]

During inspection I experienced Leakage In lean amine line which is from flange side I tried to Check all ewelds by mean of Ultrasonic testing but face following difficulties,
1.Temperature of line is at higher side i.e.250 Deg F.
2.As leakage observed from flange thats why i tried to check weld/HAZ from flange side but it was not possible because area is not enough to provide access for shear wave examination.
Do any one share with me his experience regarding
1.Is this lean amine stress corrosion cracking.
2.If yes what is the best suitable method to detect this type of cracking in remaining joints of line which is working at 250 deg f.
3. iF NO THEN WHAT TYPE OF DEFECT/LEAKAGE IS THIS ALONG WITH CAUSES.
4. Is there any alternate for scanning of joints rather then Ultrasonic shear wave testing.
Looking for your cooperation
Regards

 

[stanweld]

Have you determined that leakage is through the flange to pipe weld joint?

 

[rustbuster]

0481,

You're note is un-clear, is the leak at the weld or at the flange? You may have SCC or flow accelerated corrosion at the weld. Profile radiograpy would be a good start to qualify the damage.

Good luck

 

[0481]

To rustbuster/stanweld
Thanks for your valuable comments , leakage found on flange

 

[stanweld]

Was leaking through the body of the flange or at the flanged joint? If leakage was through the flange body, you may have more problems to come. There have been a number of instances of flanges forged from continuous cast billets, not reforging billets. Leakage was rampant on flanges so manufactured and your spool fabricator more than likely could have unknowingly purchased numerous flanges thus manufactured for your job. Also poorly performed welding repairs have been noted on flanges made in China and other emerging nations resulting in similar leakage problems.

Good luck.