How to inspect piping full of NH3 1

[etsen]

The piping would be full of liquid anhydrous ammonia for some reasons when in-service inspections are conducted. So my question is how to inpect the piping? Thank you in advance.

 

[dicksewerrat]

What are you looking for? Leaks? Internal wear?

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[MikeMet]

If you are looking for metal loss then the following apply.

If the piping is un-insulated many companies have UT crawlers that give actual wall thickness 360 deg. around. If insulated and looking for CUI you can use a technique called INCOTEST which is a type of eddy current examination that goes through the insulation to find changes in metal thickness. It is an averaging technique so follow up stripping of the insulation would be needed to get actual metal thickness. Several companies can do this inspection. This can also be used for ID metal loss, but much less reliable.

There is also long wave longitudinal UT that can be done on insulated pipe which can identifiy low points that will also need follow up by stripping insulation. Again several companies do this inspection technique

If you are looking for cracks and weld defects the have way decent method on insulated pipe is profile radiography, but it's not great. If uninsulated you can perform automated shear wave UT using a crawler to look for cracking.