Line pipe grade and schedule identification 2

[dhayes]

Is there a way to determine what grade and schedule of line pipe has been used in an installation by inspection, using nondestructive methods? I assume the wall thickness could be determined by ultrasonic measurement. With that information and the OD, one could identify the schedule. But what about pipe grade determination?

 

[TD2K]

You can get portable nuclear analyzers that will give you a material breakdown. I don't know how 'fine' a breakdown they would give you or to what degree it would allow you to identify the material. We used one that I know of when we were hot tapping connections into our glycol heat tracing system and get chewing up cutting heads. Turned out the pipe, which should have been A106 GrB was actually a chrome moly alloy. We decided that during construction, they likely had some left over from the steam system and needed some there and reused it (hopefully, that's not where my missing A-106 GrB wound up ;-)).

I don't know if it would tell you enough to be able to, for example, identify A-516 Gr 70 from another grade of A-516.

 

[aurrous]

you can determine the grade of the pipe by haivng an certified NDE tech to do a PMI (positive material identafication.) test on the pipe. Basicaly it will create a spark on the pipe, and measure the spectrum of light given off. Once the test is over, it will give you a material percentage read out. ie, 0.30 C, .25 Mo so on.
Once you have that info you can go to a ASME sec. 9 Qw/Qb 422 and find a simular metal to better guess the type/grade. Once you approximate the grade, you should be able to go threw the MDR,MDS,MTR's (material data, reports, material reveiving logs.) and figure out what it was.
For the thickness of the pipe the NDE tech can do a UT thichness test on the pipe. (make sure they take a few readings and average them out, incase the pipe has been in service,corroded, erroded, and lost thickness.

 

[dbevil]

These methods will tell what what the composition of the material is, but won't tell you what grade it is. The process of manufacture also affects the strength of materials, such as cold-working and other techniques. The only way to test the strength of materials is in destructive tensile and fracture toughness tests.