Inspection of Anhydrous Ammonia Vessel

[RNicastro]

Gentlemen,

I have been tasked with the inspection of an Anhydrous Ammonia Storage Vessel. I remember that the biggest concern was SCC in the welds but am Unsure of the extent of the testing required. It has been a while. My questions is simple.

To what extent do I need to Shear Wave the welds? Is 100% required or is spot adequate?

This is an on stream inspection so Mag Particle is not the answer. Any help is greatly appreciated.

 

[0707]

Hello Castro

Depending on the temperature of the vessel you can first do liquid dye penetrant testing on all shell welds crossings and than after the results complement your inspection with shear wave or TOFD ultrasonic scanning in an extent that make you confident. If the temperature allows it, would be useful to do some metalographic replicas. The material and story of the equipment should be taken into account. Other hypothesis is to do AE (acustic emission) to detect crack noise.

Regards

Luis

 

[aybee]

this may be out of date , but here goes. If its on stream then you cant get at the welds exposed to the ammonia to do dye check or replicas. I suggest you 100% every weld you can access presuming that most of the welds you cant get at without scaffolding..if you start to find indications of cracking, start scaffolding and keep looking ..you wont win any prizes by missing a problem ..Aybee